Regular consumption of lacto-fermented vegetables has greater effects on the gut metabolome compared with the microbiome

Abstract

The industrialisation of Western food systems has reduced the regular consumption of lacto-fermented vegetables (LFV). Consuming LFV may exert health benefits through the alteration of the gut microbiome, but the mechanisms involved remain unclear. To start understanding the possible benefits of LFV, we compared faecal microbial diversity and composition, as well as dietary habits between individuals who regularly consume LFV (n = 23) and those who do not (n = 24). We utilised microbial DNA amplicon sequencing (16S rRNA and ITS2) and untargeted metabolomics (LC–MS) to analyse stool samples. Study participants also provided three consecutive days of dietary data. Results show minor effects on microbiome composition; with the enrichment of a few microorganisms potentially associated with vegetable ferments, such as Leuconostoc mesenteroides and Rhodotorula mucilaginosa (P < 0.05), in LFV consumers. However, LFV consumption had greater effects on the faecal metabolome, with higher abundances of butyrate, acetate, and valerate (P < 0.05) and significantly greater metabolome diversity (P < 0.001). Overall, the observations of minor changes in the faecal microbiome and greater effects on the faecal metabolome from LFV consumption warrant further investigations on the health significance of LFV as regular components of the daily diet in humans.

Modulating the Human Gut Microbiome and Health Markers through Kombucha Consumption: A Controlled Clinical Study

“…By contrast, participants consumed 2 servings of kombucha for four weeks, suggesting that in our short intervention study, this fermented food threshold or magnitude may have been insufficient to induce broad microbial remodeling as observed previously (Wastyk et al, 2021). Nevertheless, our findings are in line with other studies that have reported no changes to microbiota diversity as a result of fermented food intake in comparison with controls or pre-intervention state (Alvarez et al, 2020; Berding et al, 2022; Guse et al, 2023; Taylor et al, 2020; Walsh et al, 2023). For instance, a randomized, double- blind, controlled intervention study evaluated the effect of daily consumption of two doses of a multi-strain fermented milk product for 4 weeks on the gut microbiome.…”

“…While overall shifts in microbial diversity were unaffected, our study observed that the composition of the gut microbiome was impacted by kombucha supplementation. We detected significantly altered differential abundance of selected taxa between consumers and controls at the end of intervention, a pattern consistent with earlier studies (Galena et al, 2022; Guse et al, 2023; Taylor et al, 2020; Walsh et al, 2023; Wastyk et al, 2021). Specifically, we observed the enrichment of 36 species and the concurrent depletion of 14 taxa associated with kombucha consumers.…”

“…Our study participants maintained a low fiber Western diet and it is possible that kombucha intervention on a background of Western diet has limited impact on microbial diversity in humans. Most studies have utilized a diverse mix of fermented foods (Berding et al, 2022; Guse et al, 2023; Taylor et al, 2020; Wastyk et al, 2021) in contrast to our study that relied on a single fermented food supplement approach. Furthermore, existing studies vary in the quantity as well as the type of fermented food and duration of consumption, fermented food matrices, study designs, participant characteristics and health outcomes targeted.…”