# Contrasting Effects of Probiotic Yogurt and Brown Yogurt on the Urinary Metabolites and Gut Microbial Function of Healthy Adults

## TL;DR

This study compares how two types of yogurt affect urine metabolites and gut microbes in healthy adults, revealing distinct impacts on metabolism and microbial function.

## Contribution

The study provides novel insights into how probiotic and brown yogurts differentially influence gut microbiota and host metabolism.

## Key findings

- Brown yogurt increased methylamine and TMAO in urine and altered gut microbial abundances.
- Probiotic yogurt reduced O-phosphocholine and tryptophan and increased certain beneficial microbes.
- The two yogurts affected carbohydrate and amino acid metabolism pathways differently.

## Abstract

Consuming yogurt is beneficial for healthy people, but few studies have evaluated the interactions among yogurt intake, gut microbiota, and the metabolism of healthy hosts. We aimed to compare the effects of probiotic yogurt (Yi Jun Duo; YJD) and brown yogurt (Shao Suan Nai; SSN) on urinary metabolite concentrations and gut microbial composition and function in healthy adults. The SSN was produced by
Streptococcus thermophilus
S4.02 and low‐fat (1.2%) milk, which was hydrolyzed using galactosidase and browned, and the YJD was whole milk fermented by a mixture of
Lactobacillus bulgaricus
,
S. thermophilus
,
L. acidophilus
, and
Bifidobacterium lactis
. Forty‐six healthy adults (n = 23/group) consumed the yogurts for 28 days. NMR metabolomics was then used to study the differences in the concentrations of urinary metabolites, and the composition of the intestinal microbiota was characterized using 16S rRNA amplicon sequencing. SSN consumption significantly increased the urinary concentrations of methylamine, O‐phosphocholine, trimethylamine N‐oxide (TMAO), and 3‐hydroxyisobutyrate, and reduced the abundances of the Pasteurellaceae, Enterobacteriaceae, Dorea, Megamonas, Haemophilus, and Shuttleworthia. YJD consumption reduced the concentrations of O‐phosphocholine, fumarate, and tryptophan, reduced the abundance of Collinsella, and increased the urea concentration and the abundances of the Porphyromonadaceae and Parabacteroides. Twelve metabolites differed significantly in concentration between the two groups. SSN and YJD also had differing effects on carbohydrate metabolism (pyruvate metabolism, TCA cycle, and glycolysis/gluconeogenesis) and the amino acid metabolism pathway (phenylalanine, tyrosine, and tryptophan biosynthesis, and metabolism of histidine and tyrosine), principally by regulating the TMAO and amino acid metabolism of the intestinal bacteria.

We identified differing metabolic responses to different types of yogurt. Brown yogurt mainly modulated pathways associated with human and gut microbial ammonia metabolism, whereas probiotic yogurt mainly affected amino acid metabolism.