Yogurt improves insulin resistance and liver fat in obese women with nonalcoholic fatty liver disease and metabolic syndrome: a randomized controlled trial

Abstract

Background Because consumption of conventional yogurt has beneficial effects in a healthy population, and insulin resistance (IR) is the mutual pathogenesis in nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS), we hypothesized that yogurt would ameliorate IR in patients with NAFLD and MetS. Objectives The aim of this study was to investigate the effects of yogurt on IR and secondary endpoints including liver fat, gut microbiota, and serum biomarkers of inflammation and oxidative stress in obese women with NAFLD and MetS. Methods One hundred obese women aged 36–66 y with both NAFLD and MetS were randomly assigned to consume 220 g/d of either conventional yogurt or milk for 24 wk. At baseline and week 24, we measured anthropometric indices, serum glucose, insulin, lipids, and cytokines in all participants, and liver fat and gut microbiota in 20 participants randomly selected from each group. Results Forty-eight participants from the yogurt group and 44 from the milk group completed the intervention. Compared with milk, yogurt significantly decreased the homeostasis model assessment of insulin resistance (−0.53; 95% CI: −1.03, −0.02), fasting insulin (−2.77 mU/L; 95% CI: −4.91, −0.63 mU/L), 2-h insulin (−25.5 mU/L; 95% CI: −33.0, −17.9 mU/L), 2-h area under the curve for insulin (−29.4 mU/L · h; 95% CI: −44.0, −14.8 mU/L · h), alanine aminotransferase (−4.65 U/L; 95% CI: −8.67, −0.64 U/L), intrahepatic lipid (−3.44%; 95% CI: −6.19%, −0.68%), and hepatic fat fraction (−3.48%; 95% CI: −6.34%, −0.63%). Yogurt also decreased serum LPS (−0.31 EU/mL; 95% CI: −0.48, −0.14 EU/mL), fibroblast growth factor 21 (−57.76 pg/mL; 95% CI: −86.32, −29.19 pg/mL), lipids, and biomarkers of inflammation and oxidative stress, and altered gut microbiota composition. Mediation analysis showed that yogurt may improve IR by reducing serum lipids, inflammation, oxidative stress, and LPS. Conclusions Yogurt was better than milk at ameliorating IR and liver fat in obese Chinese women with NAFLD and MetS, possibly by improving lipid metabolism, reducing inflammation, oxidative stress, and LPS, and changing the gut microbiota composition. This trial was registered at www.chictr.org.cn as ChiCTR-IPR-15006801.

Probiotic Supplementation for Rheumatoid Arthritis: A Promising Adjuvant Therapy in the Gut Microbiome Era

“…Furthermore, in patients with type 2 diabetes, the consumption of a probiotic yogurt containing 3.7 × 10 6 CFU/g of both L. acidophilus (La5) and B. lactic (Bb12), significantly decreased TNF levels (Mohamadshahi et al, 2014). A significant decrease in TNF levels, as a result of yogurt consumption, was also found in a RCT promoted by Chen et al, conducted in obese women with nonalcoholic fatty liver disease and metabolic syndrome (Chen et al, 2019). In this study conventional yogurt was used and a significant decrease in serum lipopolysaccharide (LPS), a biomarker of gut permeability, was also found as well as changes in GM composition, namely a decrease in the abundance of the Firmicutes phylum and the taxa within it (Chen et al, 2019).…”

Milk and Dairy Products and Their Impact on Carbohydrate Metabolism and Fertility—A Potential Role in the Diet of Women with Polycystic Ovary Syndrome

“…Yoghurt appears to be particularly beneficial in the prophylaxis of insulin resistance in women. A study by Chen et al [25] revealed that full-fat yoghurt significantly reduced HOMA-IR, fasting insulin levels and a 75 g 2 h oral glucose tolerance test compared to full-fat milk in women with metabolic syndrome and nonalcoholic fatty liver disease. However, the study showed significantly reduced HOMA-IR, fasting glucose and insulin levels in a group of women consuming milk, while the level of insulin in a 75 g 2 h oral glucose tolerance test significantly increased.…”

Yoghurt Consumption is Associated With Transient Changes in the Composition of the Human Gut Microbiome

“…In the same study, an increase in butyrateproducing metagenomic species was described as well as a decrease of the pathobiont Bilophila wadsorthia implying that fermented dairy product consumption may result in modi cations of the composition but also the metabolic activity of the gut microbiota [16]. More recently in a 24-week intervention conducted in obese women with NAFLD and MetX, yoghurt consumption improved insulin resistance and changed the abundance of some members of Firmicutes compared to milk [6]. Thus, part of the bene cial effects of fermented milk product including yoghurt are thought to be mediated via modulation of the gut ecosystem.…”

“…Yoghurt consumption is associated with reduced body weight gain and incidence of type 2 diabetes in epidemiological studies [3][4][5]. Randomized controlled trials have shown that yoghurt intake reduces body fat in obese subjects and insulin resistance in obese women with nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetX) [6,7].…”

“…6.1) between microbial measurements (alpha diversity; species and metabolic pathways relative abundances) and yoghurt consumption (consumer vs. non-consumer) using family structure as random effect, while age, BMI, sex, HEI as xed effects. For 16S rRNA amplicon sequencing data, sequencing run, sequencing depth, who extracted the DNA, who loaded the DNA and sample collection method were added to the model as technical co-variates.…”