Below is some of the best dairy research from October 2018! The 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.
If you would like to peruse the most pertinent dairy research from months past, then visit the Dairy Research Bulletin Archive
Selected Publications on Animal Health, Food Safety, and Sustainability
Short-term methane emissions from 2 dairy farms in California estimated by different measurement techniques and US Environmental Protection Agency inventory methodology: A case study. Arndt C, Leytem AB, Hristov AN, Zavala-Araiza D, Cativiela JP, Conley S, Daube C, Faloona I, Herndon SC. J Dairy Sci. 2018 Oct 10. pii: S0022-0302(18)30939-1.
- Reported estimates of CH4emissions from ruminants and manure management are up to 2 times higher in atmospheric top-down calculations than in bottom-up (BU) inventories.
- The researchers explored this discrepancy by estimating CH4emissions of 2 dairy facilities in California with US Environmental Protection Agency (US EPA) methodology, which is used for BU inventories, and 3 independent measurement techniques:
- (1) open-path measurements with inverse dispersion modeling
- (2) vehicle measurements with tracer flux ratio method
- (3) aircraft measurements with the closed-path method.
- All 3 techniques were used to estimate whole-facility CH4 emissions during 3 to 6 days per farm in the summer of 2016. In addition, open-path measurements were used to estimate whole-facility CH4emissions over 13 to 14 days per farm in the winter of 2017.
- The results showed that whole-facility CH4estimates were similar among measurement techniques. No seasonality was detected for CH4 emissions from animal housing, but CH4 emissions from liquid manure storage were 3 to 6 times greater during the summer than during the winter measurement periods. Manure CH4 emissions contributed 69-79% during the summer and 26-47% during the winter to whole-facility CH4 emissions measurements.
- The findings confirm previous studies showing that whole-facility CH4emissions need to be measured throughout the year to estimate and evaluate annual inventories. Additionally, the researchers suggest that manure management practices that reduce the amount of manure solids stored in liquid form could significantly reduce dairy CH4
Host genetics and the rumen microbiome jointly associate with methane emissions in dairy cows. Difford GF, Plichta DR, Løvendahl P, Lassen J, Noel SJ, Højberg O, Wright AG, Zhu Z, Kristensen L, Nielsen HB, Guldbrandtsen B, Sahana G. PLoS Genet. 2018 Oct 12;14(10):e1007580.
- Methane (CH4) is a natural by-product of gastro-enteric microbial fermentation of feedstuffs in the rumen and contributes to 6% of total CH4 emissions from anthropogenic-related sources. The extent to which the host genome and rumen microbiome influence CH4 emission is not yet well known.
- This study confirms individual variation in CH4 production was influenced by individual host (cow) genotype, as well as the host’s rumen microbiome composition. Abundance of a small proportion of bacteria and archaea taxa were influenced to a limited extent by the host’s genotype and certain taxa were associated with CH4 emissions.
- However, the cumulative effect of all bacteria and archaea on CH4 production was 13%, the host genetics (heritability) was 21% and the two are largely independent. This study demonstrates variation in CH4 emission is likely not modulated through cow genetic effects on the rumen microbiome.
- Therefore, the rumen microbiome and cow genome could be targeted independently, by breeding low methane-emitting cows and in parallel, by investigating possible strategies that target changes in the rumen microbiome to reduce CH4 emissions in the cattle industry.
Genome-wide association identifies methane production level relation to genetic control of digestive tract development in dairy cows. Pszczola M, Strabel T, Mucha S, Sell-Kubiak E. Sci Rep. 2018 Oct 11;8(1):15164.
- The global temperatures are increasing. This increase is partly due to methane (CH4) production from ruminants, including dairy cattle. Recent studies on dairy cattle have revealed the existence of a heritable variation in CH4production that enables mitigation strategies based on selective breeding.
- The researchers exploited the available heritable variation to study the genetic architecture of CH4production and detected genomic regions affecting CH4 Although the detected regions explained only a small proportion of the heritable variance, they showed that potential quantitative trait locus (QTL) regions affecting CH4 production were located within QTLs related to feed efficiency, milk-related traits, body size and health status.
- Five candidate genes were found: CYP51A1 on BTA 4, PPP1R16B on BTA 13, and NTHL1, TSC2, and PKD1 on BTA 25. These candidate genes were involved in a number of metabolic processes that are possibly related to CH4 One of the most promising candidate genes (PKD1) was related to the development of the digestive tract. The results indicate that CH4production is a highly polygenic trait.
Is rumination time an indicator of methane production in dairy cows? Zetouni L, Difford GF, Lassen J, Byskov MV, Norberg E, Løvendahl P. J Dairy Sci. 2018 Oct 3. pii: S0022-0302(18)30920-2.
- As long as large-scale recording of expensive-to-measure and labor-consuming traits, such as dry matter intake and CH4production, continues to be challenging in practical conditions, alternative traits that are already routinely recorded in dairy herds should be investigated. An ideal indicator trait must, in addition to expressing genetic variation, have a strong correlation with the trait of interest.
- The aim of the study was to estimate individual level and phenotypic correlations between rumination time, CH4 production, and dry matter intake to determine if rumination time could be used as an indicator trait for CH4 production and dry matter intake.
- Data from 343 Danish Holstein cows were collected at the Danish Cattle Research Centre for a period of approximately 3 yr. The data set consisted of 14,890 records for dry matter intake, 15,835 for rumination time, and 6,693 for CH4 Data were divided in primiparous cows only (PC) and all cows (MC), and then divided in lactation stage (early, mid, late, and whole lactation) to analyze the changes over lactation.
- The results showed that phenotypic and individual level correlations between rumination time and both CH4 production and dry matter intake were close to zero, regardless of lactation stage and data set (PC or MC). However, CH4 production and dry matter intake were highly correlated, both across lactation stages and data sets.
- In conclusion, rumination time is unsuitable to be used as an indicator trait for either CH4 production or dry matter intake.
A global strategy to mitigate the environmental impact of China’s ruminant consumption boom. Du Y, Ge Y, Ren Y, Fan X, Pan K, Lin L, Wu X, Min Y, Meyerson LA, Heino M, Chang SX, Liu X, Mao F, Yang G, Peng C, Qu Z, Chang J, Didham RK. Nat Commun. 2018 Oct 8;9(1):4133.
- Rising demand for ruminant meat and dairy products in developing countries is expected to double anthropogenic greenhouse gas and ammonia emissions from livestock by 2050. Mitigation strategies are urgently needed to meet demand while minimizing environmental impacts.
- The researchers developed scenarios for mitigating emissions under local vs global supply policies using data from 308 livestock farms across mainland China, where emissions intensities are ~50% higher than those in developed nations.
- The results showed that intensification of domestic production and globalized expansion through increased trade result in reductions in global emissions by nearly 30% over a business-as-usual scenario, but at the expense of trading partners absorbing the associated negative externalities of environmental degradation.
- Only adoption of a mixed strategy combining global best-practice in sustainable intensification of domestic production, with increased green-source trading as a short-term coping strategy, can meet 2050 demand while minimizing the local and global environmental footprint of China’s ruminant consumption boom.
Ultrafine particle emissions from natural gas, biogas and biomethane combustion. Xue J, Li Y, Peppers J, Wan C, Kado NY, Green PG, Young TM, Kleeman MJ. Environ Sci Technol. 2018 Oct 8.
- Biogas and biomethane (=purified biogas) are major renewable fuels that play a pivotal role in the evolving global energy economy.
- The study objective was to measure ultrafine particle (UFP, Dp<100 nm) emissions from the combustion of biomethane and biogas produced from five different representative sources:
- two food waste digesters
- two dairy waste digesters
- one landfill
- Combustion exhaust for each of these sources was measured from one or more representative sectors including electricity generation, motor vehicles, and household use.
- Results show that UFP emissions are similar when using biomethane and natural gas with similar sulfur and siloxane content. Approximately 70% of UFPs emitted from water heaters and cooking stoves were semi-volatile but 30% of the UFPs were non-volatile and did not evaporate even under extremely high dilution conditions.
- Photochemical aging of biomethane combustion exhaust and natural gas combustion exhaust produced similar amounts of secondary organic aerosol (SOA) formation.
- The results of the current study suggest that widespread adoption of biogas and biomethane as a substitute for natural gas will not significantly increase ambient concentrations of primary and secondary UFPs if advanced combustion technology is used and the sulfur and siloxane content is similar for biogas/biomethane and natural gas.
Host genetics and the rumen microbiome jointly associate with methane emissions in dairy cows. Evaluation of systematic California Mastitis Tests and vaginal examinations as measures of antimicrobial use in dairy herds. Krogh MA, Forkman B, Østergaard S, Houe H, Sørensen JT. Vet J. 2018 Oct;240:37-39.
- Antimicrobial use is a commonly applied proxy for animal health and welfare impairment related to disease status in dairy herds.
- The objective of this study was to estimate the association between antimicrobial use and the results of systematic clinical examinations for metritis and mastitis.
- Data was collected from 109 Danish dairy herds over a 5-year period.
- Statistical analysis demonstrated that the results of vaginal examinations and California mastitis tests on fresh cows were poor predictors of antimicrobial use at the herd level and 52% of the variance in the clinical data could be explained by herd-level factors.
- The results could be explained by the concept of a treatment threshold within each herd. We suggest that antimicrobial use should be categorised as a decision made by the herd manager rather than an approximation of disease status in the herd.
Occupational Safety and Health of Foreign-Born, Latinx Dairy Workers in Colorado. Menger-Ogle LM, Pezzutti F, Menger-Ogle A, Stallones L, Rosecrance J. J Occup Environ Med. 2018 Oct 10.
- The US dairy industry, which employs foreign-born, primarily Latinx workers, has a two-fold higher injury rate compared to the national average. Little research has been conducted to understand the factors associated with the occupational safety and health (OSH) among foreign-born, Latinx dairy workers.
- Structured interviews were conducted with 55 workers to assess a variety of OSH variables, including training experiences, health outcomes, and the psychosocial environment of the dairy.
- Participants reported a high number of work-related injuries, limited awareness of the risks inherent in dairy work, and the perception that work-related injuries are unpreventable. The psychosocial environment of the dairy was found to have a significant influence on OSH outcomes.
- In addition to implementing culturally congruent OSH training for all workers, it is imperative to promote strong leadership and communication skills among dairy managers.
Distinct phenotypic traits of Staphylococcus aureus are associated with persistent, contagious bovine intramammary infections. Grunert T, Stessl B, Wolf F, Sordelli DO, Buzzola FR, Ehling-Schulz M. Sci Rep. 2018 Oct 29;8(1):15968.
- Staphylococcus aureus causing persistent, recurrent bovine intramammary infections are still a major challenge to dairy farming. Generally, one or a few clonal lineages are predominant in dairy herds, indicating animal-to-animal transfers and the existence of distinct pathotypic traits.
- The aim of this study was to determine if long term persistence and spreading of S. aureus are associated with specific phenotypic traits, including cellular invasion, cytotoxicity and biofilm formation.
- Mastitis isolates were collected over a 3-years period from a single dairy herd, resulting in two persistent subtypes, the high within-herd prevalent subtype ST9 (CC9)-methicillin-susceptible S. aureus (MSSA), designated HP/ST9, and the low within-herd prevalent subtype ST504 (CC705)-MSSA, designated LP/ST504. Characterization of the two different coexisting persistent subtypes showed that the following phenotypic traits are particularly associated with high within-herd prevalence:
- lack of capsular polysaccharide expression
- high cellular invasiveness
- low cytotoxicity
- high biofilm/ poly-N-acetylglucosamine (PNAG) production
- By contrast to HP/ST9, LP/ST504 is characterized by the formation of colony dendrites, which may help the bacteria to access deeper tissues as niches for persistence in single animals. Thus, within a single herd, two different types of persistence can be found in parallel, allowing longtime persistence of S. aureus in dairy cattle.
- Furthermore, this study indicates that ST9 (CC9)-MSSA strains, which are currently thought to have their primary reservoir in swine and humans, can also successfully spread to new hosts and persist in dairy herds for years.
Robot milking and relationship with culling rate in dairy cows. Bugueiro A, Fouz R, Camino F, Yus E, Diéguez FJ. Animal. 2018 Oct 29:1-7.
- Cow routines and behavioral responses are altered substantially following the installation of robot milking.
- The present study was designed to analyze the effect that switching from milking parlor to automatic milking system had on the culling rate (due to various causes) of dairy cattle.
- For this purpose, culling records and causes for culling were tracked in 23 dairy farms in the Galicia region (NW Spain). The animals in these farms were monitored for 5 years.
- The data indicated that the risk of loss due to death or emergency slaughter decreased significantly following the installation of automatic milking systems. In contrast, the risk of culling due to low production, udder problems, infertility or lameness increased significantly.
- Low-production cows (such as cows in advanced lactation due to infertility) or sick cows (such as mastitic or lame cows) allegedly have a noticeable effect both on the performance and the amortization of the cost of automatic milking systems, which in turn would lead to a higher probability of elimination than in conventional systems.
Symposium review: Genomic investigations of flavor formation by dairy microbiota. McAuliffe O, Kilcawley K, Stefanovic E. J Dairy Sci. 2018 Oct 18. pii: S0022-0302(18)30989-5.
- Flavor is one of the most important attributes of any fermented dairy product.
- Dairy consumers are known to be willing to experiment with different flavors; thus, many companies producing fermented dairy products have looked at culture manipulation as a tool for flavor diversification.
- The development of flavor is a complex process, originating from a combination of microbiological, biochemical, and technological aspects. A key driver of flavor is the enzymatic activities of the deliberately inoculated starter cultures, in addition to the environmental or “nonstarter” microbiota.
- By linking genomic traits to phenotypic outputs, it is now possible to mine the metabolic diversity of starter cultures, analyze the metabolic routes to flavor compound formation, identify those strains with flavor-forming potential, and select them for possible commercial application.
- This approach also allows for the identification of species and strains not previously considered as potential flavor-formers, the blending of strains with complementary metabolic pathways, and the potential improvement of key technological characteristics in existing strains, strains that are at the core of the dairy industry.
- An in-depth knowledge of the metabolic pathways of individual strains and their interactions in mixed culture fermentations can allow starter blends to be custom-made to suit industry needs. Applying this knowledge to starter culture research programs is enabling research and development scientists to develop superior starters, expand flavor profiles, and potentially develop new products for future market expansion.
Distribution of hydrophilic and lipophilic antibacterial drugs in skim milk, cream, and casein. Ozdemir Z, Tras B, Uney K. J Dairy Sci. 2018 Oct 10. pii: S0022-0302(18)30945-7.
- This study determined the distribution of drugs to different milk fractions according to their physicochemical properties. Hydrophilic drugs tend to concentrate in skim milk, whereas lipophilic drugs tend to concentrate in cream. The concentration of a drug in casein is related to its degree of binding to milk proteins.
- Amoxicillin and tylosin were selected as prototype hydrophilic and lipophilic drugs, respectively. The study was conducted in vitro and in vivo to determine whether in vitro conditions reflect the distribution of drugs in the different milk fractions in vivo. The in vivo study was conducted using a crossover design on 6 healthy Holstein dairy cattle.
- First, amoxicillin (i.m., single dose, 14 mg/kg) was administered to cows. Following a 1-wk washout period, tylosin (i.m., single dose, 15 mg/kg) was administered. Concentrations of amoxicillin and tylosin in milk and milk fractions were measured.
- The results showed that amoxicillin accumulates less in cream and casein, suggesting that these fractions would pose a lower risk to the consumer. Tylosin was still present at the maximum residue limit (50 μg/kg) 24 h after injection in the casein fraction and 48 h after injection in the cream fraction.
Selected Articles on Dairy Intake and Human Health
Health and nutritional aspects of sustainable diet strategies and their association with environmental impacts: a global modelling analysis with country-level detail. Springmann M, Wiebe K, Mason-D’Croz D, Sulser TB, Rayner M, Scarborough P. Lancet Planet Health. 2018 Oct;2(10):e451-e461.
- Sustainable diets are intended to address the increasing health and environmental concerns related to food production and consumption. Although many candidates for sustainable diets have emerged, a consistent and joint environmental and health analysis of these diets has not been done at a regional level.
- Using an integrated health and environmental modelling framework for more than 150 countries, the researchers examined three different approaches to sustainable diets motivated by environmental, food security, and public health objectives. In this global modelling analysis, the researchers combined analyses of nutrient levels, diet-related and weight-related chronic disease mortality, and environmental impacts for more than 150 countries in three sets of diet scenarios.
- The first set, based on environmental objectives, replaced 25-100% of animal-source foods with plant-based foods. The second set, based on food security objectives, reduced levels of underweight, overweight, and obesity by 25-100%. The third set, based on public health objectives, consisted of four energy-balanced dietary patterns: flexitarian, pescatarian, vegetarian, and vegan.
- Following environmental objectives by replacing animal-source foods with plant-based ones was particularly effective in high-income countries for improving nutrient levels, lowering premature mortality and reducing some environmental impacts, in particular greenhouse gas emissions. However, it also increased freshwater use and had little effectiveness in countries with low or moderate consumption of animal-source foods.
- Following food-security objectives by reducing underweight and overweight led to similar reductions in premature mortality, and moderately improved nutrient levels. However, it led to only small reductions in environmental impacts at the global level, with reduced impacts in high-income and middle-income countries, and increased resource use in low-income countries.
- Following public health objectives by adopting energy-balanced, low-meat dietary patterns that are in line with available evidence on healthy eating led to an adequate nutrient supply for most nutrients, and large reductions in premature mortality. It also markedly reduced environmental impacts globally (reducing greenhouse gas emissions by 54-87%, nitrogen application by 23-25%, phosphorus application by 18-21%, cropland use by 8-11%, and freshwater use by 2-11%) and in most regions, except for some environmental domains (cropland use, freshwater use, and phosphorus application) in low-income countries.
- In conclusion, a public health strategy focused on improving energy balance and dietary changes towards predominantly plant-based diets that are in line with evidence on healthy eating is a suitable approach for sustainable diets. Updating national dietary guidelines to reflect the latest evidence on healthy eating can by itself be important for improving health and reducing environmental impacts and can complement broader and more explicit criteria of sustainability.
A Mediterranean diet supplemented with dairy foods improves markers of cardiovascular risk: results from the MedDairy randomized controlled trial. Wade AT, Davis CR, Dyer KA, Hodgson JM, Woodman RJ, Murphy KJ. Am J Clin Nutr. 2018 Oct 22.
- The Mediterranean diet offers benefits to cardiovascular health but may not meet Western recommendations for calcium and dairy intake, which could impede long-term adoption.
- The current study aimed to determine the effect of a Mediterranean diet supplemented with dairy foods on cardiovascular risk factors.
- A randomized, controlled, crossover design compared a Mediterranean diet with 3-4 daily servings of dairy (MedDairy) and a low-fat (LF) control diet. Forty-one participants aged ≥45 years and at risk of cardiovascular disease were randomly allocated to their first intervention, either the MedDairy or LF diet. Participants followed each intervention for 8 weeks, and an 8-week washout period separated interventions.
- The results showed that compared with the LF intervention, the MedDairy intervention resulted in a significantly lower morning systolic blood pressure, lower morning diastolic blood pressure, significantly higher HDL cholesterol, lower triglycerides, and lower ratio of total to HDL cholesterol.
- Following a MedDiet with additional dairy foods led to significant changes in markers of cardiovascular risk over 8 weeks. The MedDiet supplemented with dairy may be appropriate for an improvement in cardiovascular risk factors in a population at risk of cardiovascular disease.
Dairy Foods and Body Mass Index over 10-Year: Evidence from the Caerphilly Prospective Cohort Study. Guo J, Dougkas A, Elwood PC, Givens DI. Nutrients. 2018 Oct 16;10(10). pii: E1515.
- The association between dairy product consumption and body mass index (BMI) remains controversial.
- The aim of the present study was to investigate the association between total dairy, milk, cheese, cream and butter consumption and BMI change over a 10-year follow-up by using long-term follow-up cohort data from the Caerphilly Prospective Cohort Study (CAPS).
- The CAPS included 2512 men aged 45⁻59 years at baseline, who were followed up at 5-year intervals for over 20-year. A semi-quantitative food frequency questionnaire estimated the intake of dairy consumption, including milk, cheese, cream and butter at baseline, 5-year and 10-year follow-up. In total, men free of cardiovascular disease, diabetes and cancer (n= 1690) were included in current analysis.
- The results showed higher cheese consumption was associated with lower BMI at the 5-year follow-up. There was no evidence that higher consumption of total dairy, milk, cream and butter were significantly associated with BMI during the over the 10-year following-up.
- This study suggest that cheese consumption have beneficial effects on lowering BMI, which needs further investigation.
Fermented dairy foods intake and risk of cancer. Zhang K, Dai H, Liang W, Zhang L, Deng Z. Int J Cancer. 2018 Oct 29.
- Fermented dairy foods are known to be nutrient-rich and probiotic content, which gather optimism due to their potential in prevention and management of cancer.
- The researchers searched the PubMed, Embase and CNKI databases for all available studies through July 2018 on the association between fermented dairy foods intake and cancer risk. 61 studies met the inclusion criteria for this study, with 1,962,774 participants and 38,358 cancer cases.
- Overall, statistical evidence of significantly decreased cancer risk was found to be associated with fermented dairy foods intake in cohort studies. Yogurt consumption was significantly associated with decreased cancer risk in the overall comparison and in the cohort studies.
- In terms of subgroup analyses by cancer type, fermented dairy foods intake significantly decreased bladder cancer, colorectal cancer and esophageal cancer risk. In stratified analyses, significantly decreased colorectal cancer risk was found to be associated with cheese intake. Yogurt consumption was significantly decreased bladder cancer and colorectal cancer risk.
- This meta-analysis indicated that fermented dairy foods intake was associated with an overall decrease in cancer risk.
Intake of fermented and non-fermented dairy products and risk of incident CHD: the Kuopio Ischaemic Heart Disease Risk Factor Study. Koskinen TT, Virtanen HEK, Voutilainen S, Tuomainen TP, Mursu J, Virtanen JK. Br J Nutr. 2018 Oct 29:1-10.
- Recent dairy product studies have suggested that fermented rather than non-fermented dairy products might provide benefits on cardiovascular health, but the evidence is inconclusive. Therefore, we investigated whether fermented and non-fermented dairy products have distinct associations with the risk of incident coronary heart disease (CHD) in a population with high dairy product intake.
- The present study included a total of 1981 men, aged 42-60 years, from the Kuopio Ischaemic Heart Disease Risk Factor Study, with no CHD at baseline. Dietary intakes were assessed with instructed 4-day food records.
- During a mean follow-up of 20 years, 472 CHD events were recorded. Median intakes were 105 grams/day for fermented (87% low-fat products) and 466 grams/day for non-fermented dairy products (60% low-fat products).
- After adjusting for potential confounders, those in the highest (vs. lowest) intake quartile of fermented dairy products had 27% lower risk of CHD. In contrast, those in the highest intake quartile of non-fermented dairy products had 52% higher risk of CHD.
- When analyzed based on fat content, low-fat (<3·5 % fat) fermented dairy product intake was associated with lower risk, but high-fat fermented dairy and low-fat or high-fat non-fermented dairy products had no association. These results suggest that fermented and non-fermented dairy products can have opposite associations with the risk of CHD.
High dairy products intake reduces osteoporosis risk in Korean postmenopausal women: A 4 year follow-up study. Park SJ, Jung JH, Kim MS, Lee HJ. Nutr Res Pract. 2018 Oct;12(5):436-442.
- The aim of this study was to identify the effect of dairy products, milk and yogurt on osteoporosis incidence among Korean postmenopausal women using prospective cohort data.
- 1,573 postmenopausal women (aged 40-69 years at baseline) were eligible for the present study. Intakes of dairy products, milk, and yogurt were assessed using a validated semi-quantitative food frequency questionnaire.
- The subjects with higher frequency of dairy product consumption showed a decreased risk of radius osteoporosis after adjusting for potential confounders. Similarly, high frequency of milk and yogurt consumption had a protective effect on radius osteoporosis. However, high dairy products consumption was not related with tibia osteoporosis.
- This study suggests that daily intake of dairy products could potentially reduce radius osteoporosis incidence among Korean postmenopausal women.
Effects of Whole Milk Supplementation on Gut Microbiota and Cardiometabolic Biomarkers in Subjects with and without Lactose Malabsorption. Li X, Yin J, Zhu Y, Wang X, Hu X, Bao W, Huang Y, Chen L, Chen S, Yang W, Shan Z, Liu L. Nutrients. 2018 Oct 2;10(10). pii: E1403
- The aim of this study was to compare the impact of whole milk supplementation on gut microbiota and cardiometabolic biomarkers between lactose malabsorbers and absorbers.
- The researchers performed a pair-wise intervention study of 31 lactose malabsorbers and 31 lactose absorbers 1:1 matched by age, sex, body mass index, and daily dairy intake. Subjects were required to add 250 mL/day whole milk for four weeks in their routine diet. At the beginning and the end of the intervention period, the researchers collected data on gut microbiota and cardiometabolic biomarkers.
- Whole milk supplementation significantly increased Actinobacteria, Bifidobacterium, Anaerostipe, and Blautia; and decreased Megamonas in lactose malabsorbers, but not lactose absorbers. Microbial richness and diversity were not affected.
- The fecal levels of short-chain fatty acids (SCFAs) remained stable throughout the study. Body fat mass and body fat percentage reduced in both groups, but the changes did not differ between groups. No significant differences in other cardiometabolic markers were found between lactose malabsorbers and lactose absorbers.
- When compared with lactose absorbers, whole milk supplementation could alter the intestinal microbiota composition in lactose malabsorbers, without significant changes in fecal SCFAs and cardiometabolic biomarkers.
The combined effects of yogurt and exercise in healthy adults: Implications for biomarkers of depression and cardiovascular diseases. Kim HK, Kim SH, Jang CS, Kim SI, Kweon CO, Kim BW, Ryu JK. Food Sci Nutr. 2018 Sep 7;6(7):1968-1974.
- Several studies have reported individual benefits of yogurt and exercise on health; however, their combined effects remain unclear.
- Twenty-four healthy individuals participated in the study and were randomly assigned to the following four groups: control, yogurt, exercise, and combination.
- The participants consumed yogurt and exercised for 2 weeks, and we examined the combined effects of yogurt and exercise on physiological biomarkers.
- Individually, yogurt and exercise did not exert a significant effect on biomarkers of depression or cardiovascular disease, although vitamin D levels increased in the exercise group. However, in the combination group, serotonin levels increased, while levels of triglycerides and high-sensitivity C-reactive protein, which are biomarkers for cardiovascular diseases, decreased.
- In conclusion, the results of the study showed that, in healthy individuals, a combination of yogurt and exercise led to greater increases in serotonin levels and reductions in triglyceride and high-sensitivity C-reactive protein levels, relative to those observed for yogurt or exercise alone; therefore, this combination could have implications for the prevention of depression and cardiovascular disease.