Dairy Research Bulletin: Selected Articles from December 2025

Each month CDRF Chief Science Officer, Dr. Kevin Comerford, reviews emerging scientific articles that may have an impact on our industry, specifically from a California perspective.

The CDRF Dairy Research Bulletin delivers a brief synopsis of the most current Human, Animal, and Environmental dairy research that is going on in the world, and also that which is of special interest to California dairy producers and consumers alike. See what’s new in dairy research across topics such as environmental health, nutrition and human health effects, dairy economics, animal health and genetics, and food safety and security.

Environmental Management and Sustainability

Closing the loop in agriculture: life cycle assessment from manure to hydrogen and biofertilizer. Tehseen A, Regueiro L, Feijoo G, González-García S. Sci Total Environ. 2025 Dec 16;1011:181135.

• Dairy sector accounts for 14-20 % of global greenhouse gas (GHG) emissions where the major emissions come from manure-management and fertilizers consumption.
• To address these hotspots, a closed-loop system is developed to valorize livestock manure for simultaneous hydrogen and fertilizer production, thereby fulfilling on-farm energy and nutrient needs.
• The system, modelled using SuperPro Designer®, consists of anaerobic digestion (AD) for biogas generation, followed by steam methane reforming and a water-gas shift reaction for hydrogen production. The digestate, enriched in nitrogen, phosphorus, and potassium, serves as a biofertilizer, reducing reliance on synthetic alternatives.
• Simulation results demonstrate that the system can meet the farm’s energy demands and supply up to 32 % of its fertilizer requirements.
• Life Cycle Impact Assessment (LCA) was conducted using primary data from both the farm and the simulation model, employing an economic allocation approach within a cradle-to-gate boundary. The functional unit was defined as 1 kg of fat and protein corrected milk (FPCM).
• Two scenarios were evaluated: a conventional intensive dairy farm (Scenario-1) and the same farm with the proposed system (Scenario-2).
• Scenario-2 resulted in a significant shift in economic value towards hydrogen (63.01 %) and achieved a 66 % reduction in global warming potential per kg of FPCM without compromising milk yield.
• These results highlight the potential of integrated manure valorization systems to promote circularity and reduce the environmental footprint of dairy farming. However, there is a need to study the feasibility and scalability of this approach for different farms, climatic-regions and geographical constraints.

Transforming dairy waste into hydrogen fuel using alginate-encapsulated bacterial co-cultures. Bennett DT, Kosko RM, Meyer AS, et al. bioRxiv [Preprint]. 2025 Dec 18:2025.12.18.695156.

• Dairy waste, such as whey resulting from cheese production, is produced in massive volumes worldwide and is regarded as environmentally difficult to dispose of due to its high organic content. Harnessing the potential of this waste material to support the synthesis of valuable products such as hydrogen fuel or reduced graphene oxide, which may be utilized for conductive thin films and energy storage, can reduce waste and add revenue streams for dairy farmers.
• Here, researchers demonstrate a circular bioeconomy using alginate-encapsulated co-cultures of Shewanella oneidensistogether with lactic-acid-producing bacteria Klebsiella pneumoniae. These co-cultures can directly metabolize unprocessed cheese-making waste as an electron source instead of costly, environmentally high-impact lactic acid.
• Alginate-encapsulated co-cultures fed unprocessed dairy waste showed a 2-to-3-fold higher graphene oxide reduction rate compared to  oneidensismonocultures with no supplemental electron source. Encapsulated co-cultures were able to be recycled for more than 30 days with no measurable decrease in graphene oxide reduction efficiency, showing compatibility with future industrial scaling.
• Photocatalytic hydrogen generation with cadmium selenide quantum dots as the catalyst resulted in 6-fold increases in hydrogen produced by co-cultures using milk as an electron source precursor for the system in comparison to  oneidensismonocultures without any added electron sources.
• Thus, dairy waste may be processed to drive the synthesis of valuable products utilizing microbial electron transfer processes, converting a significant fluvial environmental pollutant into a valuable renewable energy resource that could provide a robust alternative revenue stream for dairy farmers in a volatile industry.

Acidification and nitrification inhibition of manure alters greenhouse gas emissions and nitrogen cycling in diverse agricultural soils. Wodrich MD, Hall SJ, Zhu-Barker X. J Environ Qual. 2026 Jan-Feb;55(1):e70123.

• Manure amendments are widely used in agriculture to enhance crop productivity and maintain soil organic matter, but they also contribute to greenhouse gas emissions and reactive nitrogen (N) losses.
• Manure acidification and nitrification inhibitors (NIs) have been proposed as mitigation strategies, but their effectiveness likely varies with soil characteristics.
• To evaluate the influence of acidified and NI-treated manure on N cycling across different soil types, we conducted a 28-day laboratory incubation using soils collected from major agricultural regions in Wisconsin.
• Researchers measured emissions of nitrous oxide (N₂O), nitric oxide (NO), carbon dioxide (CO₂), and methane (CH₄), along with soil ammonium (NH₄⁺) and nitrate (NO₃ ^–) dynamics.
• Acidified manure enhanced short-term NH₄⁺ retention in all soils but increased cumulative N₂O emissions in the sandy soil compared to untreated manure, likely due to pH-driven disruption of nitrification and incomplete denitrification.
• In contrast, the NI dicyandiamide (DCD) consistently suppressed nitrification early in the incubation, resulting in significantly lower N₂O and NO emissions, often approaching levels observed in the no-manure controls, particularly in the sandy soil.
• Manure amendments increased CO₂fluxes relative to the no-manure controls, but acidified manure emitted less CO₂ than DCD-treated manure, likely due to temporary suppression of microbial respiration. CH₄ emissions were minimal and largely unaffected by treatments.
• NIs offer consistent benefits in reducing N₂O and NO losses, while acidification can increase these emissions in certain soil conditions, highlighting the importance of tailoring management practices to specific soil characteristics.

Methane emissions reduced using gypsum in pilot-scale dairy manure tanks. Tomalty E, Laniel M, VanderZaag A, et al. J Environ Qual. 2026 Jan-Feb;55(1):e70112.

• Animal manure storage facilities are sources of greenhouse gas emissions in Canada, with the majority of emissions in the form of methane and nitrous oxide.
• This study was conducted to assess how effective adding gypsum powder to cow manure is at reducing the emissions of methane and nitrous oxide.
• At a pilot-scale research facility in Nova Scotia, Canada, gypsum powder was added to tanks containing ∼10,000 L of local dairy manure in duplicate at three rates: low rate (3.2 g L^-1), high rate (7.1 g L^-1), and the control (0 g L^-1).
• Each manure tank was enclosed within a steady-state chamber, and gas samples were manually taken using a syringe from the exhaust into pre-evacuated vials at regular intervals between June and November (143 days).
• Using gas chromatography, methane and nitrous oxide measurements were analyzed from each vial, allowing for calculations of cumulative emissions and CO₂-e.
• Compared to the control, both the high rate and low rate of gypsum significantly reduced cumulative methane emissions. Though the cumulative nitrous oxide emissions were reduced using both rates of gypsum, the nitrous oxide emissions were minor and not statistically significant.
• Methane emissions were reduced by 87% using the low rate of gypsum and by 92% using the high rates of gypsum.
• Gypsum additive to slurry in storage facilities is a safe and effective mitigation strategy to reduce greenhouse gas emissions. Further research is required to support on-farm application rates and feasibility.

Transmission of core gut microbiota through earthworm cocoons: Insights from bacterial community structure and function across different composting systems. Pang C, Chen D, Dai L, Zhang Y, Zhao H, Hu J. Bioresour Technol. 2025 Dec 29:133906.

• Earthworm endophytic microbiota is crucial for maintaining their health and supporting their function in organic waste decomposition. However, the mechanisms of their intergenerational transmission and ecological stability are unclear.
• Researchers investigated the role of cocoons, gut walls, and castings as microbial vectors using 16S rRNA sequencing under three composting systems (fermented coffee residue, cattle manure, and sewage sludge).
• A highly conserved core microbiota, dominated by Pseudomonadota (45-60 %) and Actinomycetota (15-25 %), was identified in cocoons. The substrate influenced its diversity, but core members remained stable. 37-92 % OTU sharing between parental cocoons and offspring guts confirmed vertical transmission.
• The core community significantly shaped the microbiota of castings. Functional prediction indicated its potential role in nitrogen and carbon cycling. Cocoons are key vehicles for vertical transmission of core microbiota, ensuring functional continuity across generations.
• This highlights their importance in sustainable waste conversion and offers potential for application in agriculture and ecosystem restoration.

Animal Health and Food Safety

Converging threats: The intersection of seasonal influenza surges and zoonotic highly pathogenic avian influenza. Yang W, Xiong H, Lu H, et al. Glob Health Med. 2025 Dec 31;7(6):409-413

• The global landscape of influenza is becoming increasingly complex. In the Northern Hemisphere, seasonal influenza activity is exhibiting a pattern of “early onset, high intensity”. At the same time, highly pathogenic avian influenza (HPAI) continues to circulate widely among wild birds and poultry, with a growing tendency to spillover into mammals, including dairy cattle, thereby substantially increasing the zoonotic risk.
• This convergence exposes the limitations of control systems that manage human and animal influenza separately. Given the ongoing cross-species adaptive evolution of influenza viruses at the human-animal-environment interface, global strategies need to pivot toward a fully integrated One Health paradigm as the organizing principle for preparedness and response.
• By synthesizing surveillance data and research capacity across human, animal, and environmental health sectors, the international community can build a more resilient defense network that both reduces the current disease burden and helps pre-empt the emergence of novel pandemic strains arising from viral reassortment.

Development of an Infectious Disease Vulnerability Index (IDVI) for dairy farms: A data-driven approach to assessing risk and informing biosecurity practices. Osuagwu JU, Smith JM, Merrill SC. Prev Vet Med. 2025 Dec 18;247:106770.

• Dairy farms are vulnerable to a wide range of infectious diseases, which can have significant economic and public health consequences. However, there remains a lack of a robust, farm-level tool that assesses their disease vulnerability.
• The primary objective of this study was to develop and validate the Infectious Disease Vulnerability Index (IDVI) as a tool for assessing dairy farm vulnerability to disease, aimed at enhancing biosecurity strategies and prioritizing high-risk farms for targeted interventions.
• Survey data on biosecurity practices, farm management, and animal movement were analyzed using K-Prototypes clustering, dimensionality reduction, optimal cluster determination, stability assessment, and validation.
• The clustering analysis revealed three distinct farm clusters, characterized by low, medium, and high disease vulnerability index categories.
• Following permutation testing, the factors with the most impact on the infectious disease vulnerability clusters included specific farm characteristics such as organic status and the total number of dairy animals, animal movement practices including frequency of bull calf movements and the average number of heifers leaving the farm during a shipment.
• These factors were also important – farm contacts including hunters and dead animal haulers, and farm biosecurity practices including farm equipment transport practices, engaging in dairy animal exhibitions, and not having quarantine facilities with water, feed, and air separated from other farm animals.
• The IDVI offers a promising measure of comparing disease risk profiles, validated through bootstrapped silhouette scoring, statistical analysis, and permutation importance analysis.
• By leveraging the IDVI, dairy farmers, veterinarians, and animal health authorities can identify high-risk farms, implement targeted interventions to improve biosecurity, reduce disease transmission, and consequently enhance their outbreak preparedness.

Cow-level factors associated with risk of clinical highly pathogenic avian influenza H5N1 infection and impacts on health and productivity in lactating dairy cattle. Olthof L, Krogstad KC, Bradford BJ. J Dairy Sci. 2025 Dec 31:S0022-0302(25)01054-9.

• As highly pathogenic avian influenza (HPAI) spreads in US dairy herds, substantial uncertainty remains regarding modes of transmission and net impacts on cattle health and productivity.
• The objectives of this study were to identify factors associated with risk of clinical HPAI diagnosis (cHPAI) among lactating cows and quantify subsequent productivity and health outcomes of cHPAI versus nonclinical (NC) cows.
• Researchers used herd management data from a dairy farm in Michigan that experienced an HPAI outbreak in May 2024. Over 13 days, 28.3% of the herd’s lactating cows (932/3,293) exhibited clinical signs and were treated for HPAI.
• Univariate analysis demonstrated greater risk of diagnosis for multiparous versus primiparous cows (OR 2.36); pregnant versus not (OR 1.45); ≥100 DIM versus <100 DIM (OR 1.66); and greater milk yield (OR 1.013 per kilogram per day).
• Multivariate modeling retained parity, the quadratic effect of DIM, and pregnancy status as risk factors for cHPAI diagnosis. After accounting for DIM, pregnancy tended to be protective rather than increasing risk of HPAI diagnosis (OR 0.71), with peak risk occurring for nonpregnant cows in their fifth lactation at 220 DIM.
• Effects of HPAI diagnosis in the same lactation were assessed with data from 9 test days from May 2024 to January 2025. At 25 days after onset, cHPAI cows produced 15.1 ± 0.40 kg/d less ECM, and SCS increased 1.89 ± 0.07 units relative to NC cows. The SCS no longer differed between groups at 98 days post-onset, but ECM yield remained significantly different through 224 days after the outbreak (-4.60 ± 0.63 kg/d).
• Primiparous cows had a lesser ECM reduction than multiparous cows (-2.05 ± 0.60 vs. -7.39 ± 0.66 kg/d for parity 1 vs. 3). Protein concentrations increased subtly in cHPAI cows at 25 days and 56 days post-outbreak compared with NC.
• Clinical HPAI cows had a 1.74-fold greater hazard of death and a 2.61-fold greater hazard of culling during the ongoing lactation compared with NC. Clinical HPAI and NC cows did not differ in the odds of abortion, mastitis, or having at least 1 adverse health event.
• In summary, primiparous cows were at lesser risk for cHPAI and suffered less production losses than multiparous cows. Milk production of cHPAI cows was impaired for more than 7 months after HPAI onset, far longer than the effects on SCS. Clinical HPAI diagnosis was strongly associated with subsequent hazards of death and culling.

Integrative assessment of the effects of ventilation systems on economic efficiency, milk production, and reproductive performance in dairy cows. Peker A, Magrin L, Trestini S, et al. Front Vet Sci. 2025 Dec 4;12:1713828.

• Due to global warming, temperate regions are increasingly experiencing heat waves, which negatively impact dairy cow welfare, productivity, and farm profitability. Ventilation systems (VSs) are a common heat mitigation strategy, despite their high initial investment cost.
• This study investigated the effects of heat stress (HS) and VSs on dairy cows’ milk yield and whether VSs guarantee an economic benefit for farmers.
• The trial involved four dairy farms over 3 years: 2 years before and one after VS installation. Researchers conducted an observational within-farm pre-post study, using two pre-installation years and 0.5-1 post-installation year per farm. The following outcomes were analyzed at the herd level: daily milk yield, biweekly milk quality, and monthly reproductive metrics.
• The temperature-humidity index (THI) was calculated daily as a measure of HS and categorized as follows: comfort (<72), mild discomfort (72-79), discomfort (80-84), and alert (>84). Economic sustainability was assessed through partial budget analysis, accounting for additional feed, labor, and electricity costs.
• The presence of VSs was associated with a significant increase in cows’ milk yield across all THI conditions (p< 0.001). Fat and protein contents decreased following VS installation, consistent with the observed increase in milk yield. However, their values were significantly lower under the most critical THI classes (p < 0.001).
• Linear somatic cell count (SCC) scores were higher under the discomfort and alert THI classes in the absence of VSs, whereas they decreased slightly across THI classes when VSs were used (p< 0.001).
• The duration of lactation, days open, and number of services per pregnancy reached their highest values under THI alert conditions in the absence of VSs and were significantly reduced following the implementation of VS (p< 0.001).
• Increased milk income with VS use was €12.39/day/cow under mild discomfort, €12.23 under discomfort, and €12.08 under alert conditions. The results showed wide variability in economic outcomes across farms and THI classes.
• Although differences in VS management prevented a definitive conclusion regarding return on investment (ROI), the findings suggest positive effects on cows’ productivity and farm profitability.

Heat stress compromises nutritional quality and flavor of bovine raw milk: Evidence from multi-omics analyses. Zhao Y, Wang F, Jiang L, et al. Food Chem X. 2025 Dec 3;32:103361.

• Heat stress is a growing concern for dairy production under global climate change.
• This study employed integrated multi-omics approaches to investigate how heat stress affects the antioxidant capacity, microbiota, metabolite profiles, lipid composition, and flavor compounds in raw milk.
• Results revealed that heat stress reduced antioxidant levels and altered the milk microbiome, favoring potentially spoilage-associated bacteria.
• Metabolomic analysis indicated disrupted energy, amino acid, and lipid metabolism, with reductions in beneficial unsaturated fatty acids, conjugated linoleic acid, and polar lipids such as phosphatidylcholine and sphingomyelin.
• Notably, several off-flavor volatiles, including hexanal, ketones, and sulfur compounds, increased in heat-stressed milk, while sweet esters declined.
• These compositional and sensory changes may compromise milk quality, nutritional value, and consumer acceptability.
• This study provides a comprehensive biochemical basis for understanding how heat stress affects milk quality, offering important references for quality assessment and risk monitoring in dairy production under warming climates.

Advanced Non-Thermal Processing: Combined Cold Plasma and Pulsed Electric Field for E. coli Inactivation in Milk. Taki K, Samani BH, Ghatrehsamani S. Food Sci Nutr. 2025 Dec 29;14(1):e71408.

• Milk, rich in proteins, vitamins, and bioactive compounds, is highly susceptible to microbial contamination by pathogens like Escherichia coli, posing risks to food safety. Conventional thermal pasteurization often degrades nutritional and sensory qualities.
• This study developed a non-thermal ACP-PEF system to inactivate  coliwhile preserving milk’s properties.
• Using Response Surface Methodology (RSM) with a Box-Behnken design, four parameters, electric field strength (5-10 kV/cm), exposure time (5-35 s), argon-to-air ratio (0-1), and nozzle angle (0°-90°) were optimized via Design-Expert software.
• Optimal conditions (10 kV/cm, 35 s, ratio 0, angle 53.87°) achieved a 4.656-log reduction (99.9978%) in  coli.
• Quality analysis revealed minimal changes: pH (0.44%), fat (10%), protein (7%), lactose (7%), SNF (4%), and FFP (2%) reduction, compared to untreated milk, outperforming thermal pasteurization (reductions of 2%-20%). Color difference (ΔE = 0.81 ± 0.10) was insignificant.
• The ACP-PEF system, combining electroporation and RONS, offers a scalable, energy-efficient alternative for safe, high-quality milk production.

 

Nutrition and Health

Dairy consumption and cardiovascular disease risk: a multi-level analysis with inflammatory biomarker mediation. Ma D, Cheng X, Fang Q, Ni S, Wang F, Hu P. Nutr Metab (Lond). 2025 Dec 22.

• Including dairy products in the diet may help reduce the risk of developing cardiovascular disease (CVD). Nevertheless, how various categories of dairy items influence CVD risk remains insufficiently explored.
• This study aimed to evaluate the associations between different types of dairy products, their intake frequency, fat content, and the risk of CVD, addressing existing research gaps.
• Dairy intake data-including yogurt, cheese, and milk-were obtained from the Global Dietary Database, covering 185 countries between 1990 and 2018. Corresponding CVD burden metrics-including incidence, prevalence, and disability-adjusted life years (DALYs)-were extracted from the Global Burden of Disease study.
• These data were used to investigate how dairy intake relates to CVD burden globally. Additionally, individual-level data from 30,341 participants in the National Health and Nutrition Examination Survey (NHANES) were analyzed to evaluate the association between dairy product consumption and CVD risk.
• Globally, individuals who consumed greater amounts of milk tended to have a lower risk of CVD. Individually, milk intake was found to be negatively associated with the risk of CVD, coronary heart disease (CHD), and heart attack (HA).
• Exploratory mediation analysis indicated that systemic inflammatory markers (SIRI), the monocyte-to-lymphocyte ratio (MLR), and the neutrophil-to-lymphocyte ratio (NLR) partially mediated the relationship between milk intake and CVD risk, contributing – 6.09%, -5.02%, and – 4.13% of the total association, respectively.
• Further analysis showed that individuals who reported drinking milk daily or at least weekly tended to have a lower risk of developing CVD than those who consumed it less than once per week.
• In conclusion, milk intake may offer protective effects against CVD, CHD, and HA, potentially through the mitigation of inflammation. The frequency of milk intake appears to be a key factor influencing CVD risk.
• These findings highlight the potential public health benefits of promoting regular milk intake as part of a balanced dietary pattern to help reduce the global burden of CVD.

Fatty acid composition of dairy products and their impact on atherogenicity and thrombogenicity. Rashidimehr A, Mohammadi-Nasrabadi F, Esfarjani F, et al. Sci Rep. 2025 Dec 11;15(1):43613.

• This study aimed to assess lipid quality indices in various dairy products.
• A total of seventy samples representing seven commonly consumed dairy products, including milk, yogurt, doogh, kashk, cheese, cream, and ice cream, were randomly collected from chain stores in Iran.
• The fatty acid composition of these samples was analyzed using gas chromatography (GC), and lipid quality indices were calculated using the appropriate equations.
• The results showed that cream and fermented dairy products had the highest concentrations of short-chain fatty acids (SCFAs), while ice cream had the lowest levels of SCFAs but the highest concentration of conjugated linoleic acid (CLA), which accounted for 7.27% of the total fatty acids.
• Cheese and cream were rich in medium-chain fatty acids (MCFAs), whereas yogurt contained the highest proportion of long-chain saturated fatty acids, making up 46% of the total fatty acids.
• Additionally, ice cream exhibited the most favorable lipid quality indices, characterized by lower atherogenicity (AI: 1.70 ± 0.87) and thrombogenicity (TI: 2.54 ± 0.32), along with a superior hypocholesterolemic/hypercholesterolemic (H/H) ratio of 0.92 ± 0.16.
• Overall, significant differences (p < 0.05) were found among the primary groups of fatty acids and their corresponding healthy lipid indices, depending on the type of dairy products analyzed. These findings can assist food policy makers in identifying practical solutions for the development of the dairy industry and in promoting healthier dairy products to support public health.

High- and Low-Fat Dairy Consumption and Long-Term Risk of Dementia: Evidence From a 25-Year Prospective Cohort Study. Du Y, Borné Y, Sonestedt E, et al. Neurology. Dec 2025;106(2):e214343.

• The association between dairy intake and dementia risk remains uncertain, especially for dairy products with varying fat contents.
• The aim of this study was to investigate the association between high-fat and low-fat dairy intake and dementia risk.
• This study used data from a prospective cohort in Sweden, the Malmö Diet and Cancer cohort, which consisted of community-based participants who underwent dietary assessment at baseline (1991-1996).
• Dietary intake was evaluated using a comprehensive diet history method that combined a 7-day food diary, a food frequency questionnaire, and a dietary interview. Dementia cases were identified through the Swedish National Patient Register until December 31, 2020, and cases diagnosed until 2014 were further validated.
• The primary outcome of the study was all-cause dementia, and the secondary outcomes were Alzheimer disease (AD) and vascular dementia (VaD).
• This study included 27,670 participants (mean baseline age 58.1 years, SD 7.6; 61% female). During a median of 25 years of follow-up, 3,208 incident dementia cases were recorded.
• Consumption of ≥50 g/d of high-fat cheese (>20% fat) was associated with a reduced risk of all-cause dementia (HR 0.87) and VaD (HR 0.71) compared with lower intake (<15 g/d). An inverse association between high-fat cheese and AD was found among APOEε4 noncarriers (HR 0.87).
• Compared with no consumption, individuals consuming ≥20 g/d of high-fat cream (>30% fat) had a 16% lower risk of all-cause dementia (HR 0.84). High-fat cream consumption was inversely associated with the risk of AD and VaD.
• Consumption of low-fat cheese, low-fat cream, milk (high-fat and low-fat), fermented milk (high-fat and low-fat), and butter showed no association with all-cause dementia.
• Higher intake of high-fat cheese and high-fat cream was associated with a lower risk of all-cause dementia, whereas low-fat cheese, low-fat cream, and other dairy products showed no significant association. APOEε4 status modified the association between high-fat cheese and AD.

Effects of a probiotic fermented dairy product on hippocampal metabolites, structure and function: an 8-week randomized, placebo-controlled trial in healthy women. Marx W, Suo C, Dissanayaka T,  Jacka FN, et al. Gut. 2025 Dec 18:gutjnl-2025-335398.

• Fermented foods are a promising yet underexplored intervention for influencing brain function and mental health through the gut-brain axis.
• The objective of this study was to evaluate the impact of a dairy product fermented with probiotic bacteria on aspects of brain structure and function.
• In a triple-blind, randomized, placebo-controlled trial, 40 healthy women aged 18-55 years were randomized to consume either 130 g per day of a fermented probiotic yoghurt or a placebo for 8 weeks.
• The primary outcome was the between-group differential change from baseline to week 8 in left hippocampal metabolites, measured using magnetic resonance spectroscopy. Secondary outcomes included changes in brain structure and function, fecal microbiome composition and functional potential, mental health, gastrointestinal symptoms, memory and blood markers of oxidative stress and inflammation.
• There was a between-group difference in the change in average left hippocampal glutathione concentration (mean difference in change: -0.49), as well as brain volume in the hippocampus and nucleus accumbens, although these results did not withstand correction for multiple comparisons.
• There were between-group differences in the change in average functional connectivity between the left hippocampus and left frontal pole. There was also a significant between-group change in gut microbiome beta diversity. There were no differences in other secondary measures.
• This study provides preliminary evidence that a probiotic fermented dairy product can modulate hippocampal-related outcomes.

Effects of Supplementation with Milk Proteins on Body Composition and Anthropometric Parameters: A Systematic Review and Dose-Response Meta-Analysis. Mohammadi S, Ashtary-Larky D, Asbaghi O, et al. Nutrients. 2025 Dec 12;17(24):3877.

• There is no consensus regarding the impacts of supplementation with milk proteins (MPs) on body composition (BC).
• This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) assessed the effects of MP, casein protein (CP), and whey protein (WP) supplementation on BC and anthropometric parameters.
• A comprehensive search was performed in several databases to identify eligible RCTs published until October 2025. Random-effects models were applied to estimate the pooled effects of MP supplementation on anthropometric parameters.
• A total of 150 RCTs were included. MP supplementation substantially increased lean body mass (LBM) (weighted mean difference (WMD): 0.41 kg; p< 0.001) and fat-free mass (FFM) (WMD: 0.67 kg; p < 0.001). It also significantly reduced body fat percentage (BFP) (WMD: -0.66%; p = 0.001), fat mass (FM) (WMD: -0.66 kg; p < 0.001), and waist circumference (WC) (WMD: -0.69 cm; p = 0.004).
• No considerable effects were observed for muscle mass (MM), body mass index (BMI), and body weight (BW).
• Dose-response analysis revealed that MP dosage was associated with significant changes in BFP, LBM, and MM.
• In conclusion, MP supplementation was associated with favorable modifications in body composition, including increases in LBM and FFM, as well as reductions in FM, BFP, and WC. These findings provide coherent and consistent evidence supporting the potential role of MP supplementation in targeted body composition management.

 

Innovation, Social Science, and Dairy Alternatives

Whey-A Valuable Technological Resource for the Production of New Functional Products with Added Health-Promoting Properties. Czarniecka-Skubina E, Pielak M, Zielińska D, et al. Foods. 2025 Dec 10;14(24):4258.

• Whey, a by-product of cheese and casein manufacture, represents a major output in dairy processing and a valuable resource for the production of functional foods. Over time, whey has evolved from being regarded as waste product to becoming a strategic ingredient in the formulation of modern functional foods and bio-based materials.
• This review examines the technological, environmental, and nutritional aspects of whey valorization, emphasizing its transformation from an ecological burden to a raw material with high economic potential.
• Data from January 2015 to October 2025 were collected from PubMed, Web of Science, and Scopus to outline global whey production, utilization rates, and emerging processing methods.
• Modern membrane, enzymatic, and non-thermal technologies enable the recovery of valuable components, including proteins, lactose, and bioactive compounds. The use of these techniques reduces the biochemical and chemical oxygen demand in wastewater.
• The review highlights the use of whey in functional beverages, milk and meat processing, edible films, bioplastics, and biofuels, as well as its microbiological and biotechnological potential.
• Results indicate that only about half of the 180-200 million tons of whey produced annually is effectively valorized, underscoring the need for integrated circular-economy approaches.
• Overall, whey valorization contributes to sustainable food production, environmental protection, and the development of innovative, health-promoting products that align with global strategies for waste reduction and the development of functional foods.

Proteins supplements and protein-containing products use in ice cream – A review. Mykhalevych A, Polishchuk G, Kluz M, Buniowska-Olejnik M. J Nutr. 2025 Dec 27:101290.

• The increasing demand for high-protein diets, driven by health-conscious consumers and global nutritional challenges, has sparked interest in fortifying popular food products such as ice cream with protein ingredients.
• Ice cream, a widely consumed dessert, typically offers limited nutritional value, particularly in protein content. This review provides a comprehensive overview of protein supplementation in ice cream production, focusing on functional and technological effects of conventional and emerging protein sources.
• The paper critically evaluates milk-derived proteins, as well as underexplored alternatives including plant-based, microbial, insect-derived, and aquatic proteins. It also addresses legislative constraints, sensory and textural challenges, and formulation strategies for optimizing product quality and consumer acceptance.
• The integration of proteins into ice cream not only enhances its nutritional profile but also offers potential for market innovation aligned with sustainability and health trends. However, the successful incorporation of these ingredients into ice cream systems requires navigating complex challenges related to formulation performance, sensory quality, regulatory compliance, and consumer acceptance.
• Functional variability, sensory trade-offs, and limited industrial validation continue to hinder mainstream adoption, especially for novel protein sources. Future advances will depend on a deeper mechanistic understanding of protein behavior in multiphase frozen matrices, as well as the development of formulation strategies that reconcile nutritional value with sensory appeal.

Advances in GABA-Enriched Yogurt and Frozen Yogurt: Microbial Biosynthesis, Functional Properties, and Health Perspectives-A Comprehensive Review. Ushidee-Radzi MA, Shin Yee C, Wan-Mohtar WAAQI, et al.Foods. 2025 Dec 10;14(24):4254.

• Gamma-aminobutyric acid (GABA) is a bioactive, non-protein amino acid recognized for its role as an inhibitory neurotransmitter in the human central nervous system. Increasing interest in functional foods has increased attention on GABA due to its potential health benefits, including antihypertensive, anxiolytic, antidepressant, and neuroprotective effects.
• This review summarizes the natural dietary sources of GABA and explores advanced strategies for enriching dairy products, particularly yogurt and frozen yogurt (froyo), with GABA.
• Key microbial species capable of GABA biosynthesis via the glutamate decarboxylase (GAD) pathway are discussed, alongside enzymatic production techniques that support controlled GABA synthesis.
• A major focus of this review is the evaluation of various methods for incorporating GABA into dairy matrices, including direct GABA fortification and in situ fermentation using GABA-producing strains, with comparisons of yield, sensory attributes, and product stability.
• Furthermore, the review outlines the therapeutic effects of GABA-fortified foods and their potential roles in managing hypertension, stress, and neurodegenerative disorders.
• Key challenges, including strain-dependent variability in GABA-production, storage stability, and regulatory compliance are addressed, along with market and legislative considerations for GABA-fortified foods.
• Future perspectives include the development of novel high GABA-producing strains, process optimization to improve product stability and sensory acceptance, and expanded applications within the functional food sector.
• Overall, this review provides an integrated, up-to-date overview of technological, functional and regulatory aspects, offering a clear scientific foundation for the development and commercialization of GABA-fortified dairy products.

Effect of Nanobubbles on Ultrafiltration Membrane Performance and Properties of Model Cheese Whey. Akshit F, Bharti SK, Mohan MS. Foods. 2025 Dec 9;14(24):4224.

• Fouling has been a major concern in membrane processing, requiring frequent cleaning, increasing the time of processing, and reducing the lifespan of membranes.
• As a strategy to improve membrane filtration processes, this study investigates the impact of nanobubbles (NBs) on the whey ultrafiltration (UF) process and provides insights into the resulting changes in permeation flux, concentration factor, composition, particle charge and size, viscosity, and protein secondary structures.
• NBs led to significantly enhanced permeation flux up to 60 min (p< 0.05), leading to a higher concentration factor with time, as indicated at 120 min compared to the control. There was a significant increase in protein and total solids concentrations (33 ± 10% and 28 ± 5%) in the final retentate at 120 min for NB-treated cheese whey (NBW) as compared to the control (p < 0.05).
• While particle size is relatively unchanged with and without NB treatment, increased viscosity in NBW is caused by the increased concentration factors achieved with higher flux for the NBW by the end of UF.
• Overall, membrane efficiency was enhanced by significantly increasing peak flux and concentration factor (34 ± 5% and 40 ± 4%) for NBW compared to CW.
• This study presents an innovative approach to reach the targeted total solids/protein for cheese whey concentration in significantly less processing time (28.27% ± 2.33 reduction), with potential energy savings.
• Therefore, nanobubble technology shows promising potential to improve membrane filtration in the dairy industry with higher permeation flux, reduced fouling, and improved membrane processing efficiency.

Optimization of solid-state fermentation conditions for high beta-galactosidase-producing lactic acid bacteria and its application in low-lactose dairy products. Zhang Z. Front Bioeng Biotechnol. 2025 Dec 11;13:1708601.

• Lactose intolerance affects 85%-95% of Chinese adults, creating substantial demand for low-lactose dairy products.
• This study aimed to develop a cost-effective β-galactosidase production process through solid-state fermentation (SSF) using agricultural byproducts.
• A high-yielding strain was isolated from Tibetan fermented yak milk and identified through morphological, biochemical, and 16S rDNA sequence analysis. Solid-state fermentation conditions were optimized using single-factor experiments and Box-Behnken response surface methodology.
• Lactobacillus plantarum LP-15 exhibited initial enzyme activity of 44.7 U/g. Optimal SSF conditions were determined as substrate ratio of wheat bran:soybean meal:whey powder (6:3:1), 37 °C, pH 6.5, and 55% moisture content, achieving enzyme activity of 186.3 U/g (4.17-fold improvement).
• The enzyme exhibited optimal activity at pH 6.5 and 42 °C, with Km of 2.8 mM and catalytic efficiency of 5.3 × 10⁴M^-1s^-1. Milk lactose was reduced by 81.9% within 4 h using 2.0 U/mL enzyme at 40 °C, meeting the low-lactose standard (≤0.1%).
• SSF reduced production costs by 35.7%, water usage by 94%, and CO₂emissions by 62.4% compared to liquid fermentation.
• This study provides an economically viable and environmentally sustainable solution for low-lactose dairy production in China, establishing independent intellectual property rights while addressing nutritional needs of lactose-intolerant populations through circular utilization of agricultural by products.

What is the role of plant-based alternatives to animal foods in the Great Food Transformation? A narrative review. Rosane BP, Okoren L, Andersen BV, Byrne DV, Bügel SG. J Nutr. 2025 Dec 29:101275.

• Several plant-based alternatives to animal foods (PBAFs) have been introduced in the market in the past decade to provide consumers with an easy substitution for animal protein. Despite the extensive literature on the nutritional composition of these plant-based products, these products must be assessed considering their impacts on diets, the environment and society.
• This critical review aims to evaluate the role of plant-based alternatives to animal foods in the Great Food Transformation and their potential health effects.
• Results of nine diet modelling studies have indicated that substituting animal foods with plant-based alternatives would put certain populations at risk of inadequate intake of micronutrients, particularly of bioavailable iron, vitamin B12, calcium and iodine.
• Nutritional composition studies have shown that meat alternatives are generally similar to meat in protein and micronutrient content but with higher carbohydrates and sodium.
• Milk and yoghurt alternatives made from cereals, coconut, and nuts have significantly lower protein levels compared to their animal counterparts, while soy-based alternatives are the most comparable to animal dairy products.
• This review shows that there are nutritional pitfalls from the substitution of animal foods with PBAFs.