Investigation on the impact of Molkosan, a fermented whey rich in lactic acid, on insulin levels, short-chain fatty acid profiles, and the gut microbiota of healthy adults.

Consumption of fermented foods (e.g. yoghurt, sauerkraut) may have considerable health-promoting effects by delivering a variety of bioactive and nutritive compounds to the gastrointestinal tract. In this proof of concept study, the effect of daily consumption of a fermented whey concentrate rich in (L+)-lactic acid was investigated in 18 healthy men (n=5) and women (n=13) in free-living conditions. The aim of this 6-week trial was to (i) identify changes in the gut microbiota composition and faecal short chain fatty acid (SCFA) profile, and (ii) to monitor changes in glucose homeostasis and insulin sensitivity. After completion of the 6-week trial period, total faecal SCFA concentration remained constant throughout the intervention (week 6). Proportionally, there was a significant change in the SCFA composition compared to baseline. Acetate levels were reduced (67.0% to 60.5%; p<0.01), coupled to an increase in the relative amounts of propionate (+2.2%; p<0.01) and butyrate (+4.2%; p<0.01), respectively. Notably, after six weeks of daily consumption, fasting insulin levels had decreased significantly by 0.11 mU/l (-34.74%, SEM±7.9, p=0.01; n=17), matched by reductions in HOMA-IR and HOMAßcell.Overall, the observed change in fasting insulin levels provides first insight of the potential of (L+)-lactic acid to favourably influence glycaemic indicators in healthy adults. In contrast, the changes in the faecal SCFA profile can`t be linked to a change in the faecal microbiota composition. Future rigorous trials are needed to clarify the biological mechanisms involved in the observed changes in health biomarkers