Lactobacillus rhamnosus GG modifies the metabolome of pathobionts in gnotobiotic mice

Abstract

Background Lactobacillus rhamnosus GG (LGG) is the most widely used probiotic, but the mechanisms underlying its beneficial effects remain unresolved. Previous studies typically inoculated LGG in hosts with established gut microbiota, limiting the understanding of specific impacts of LGG on host due to numerous interactions among LGG, commensal microbes, and the host. There has been a scarcity of studies that used gnotobiotic animals to elucidate LGG-host interaction, in particular for gaining specific insights about how it modifies the metabolome. To evaluate whether LGG affects the metabolite output of pathobionts, we inoculated with LGG gnotobiotic mice containing Propionibacterium acnes, Turicibacter sanguinis, and Staphylococcus aureus (PTS). Results 16S rRNA sequencing of fecal samples by Ion Torrent and MinION platforms showed colonization of germ-free mice by PTS or by PTS plus LGG (LTS). Although the body weights and feeding rates of mice remained similar between PTS and LTS groups, co-associating LGG with PTS led to a pronounced reduction in abundance of P. acnes in the gut. Addition of LGG or its secretome inhibited P. acnes growth in culture. After optimizing procedures for fecal metabolite extraction and metabolomic liquid chromatography-mass spectrometry analysis, unsupervised and supervised multivariate analyses revealed a distinct separation among fecal metabolites of PTS, LTS, and germ-free groups. Variables-important-in-projection scores showed that LGG colonization robustly diminished guanine, ornitihine, and sorbitol while significantly elevating acetylated amino acids, ribitol, indolelactic acid, and histamine. In addition, carnitine, betaine, and glutamate increased while thymidine, quinic acid and biotin were reduced in both PTS and LTS groups. Furthermore, LGG association reduced intestinal mucosal expression levels of inflammatory cytokines, such as IL-1α, IL-1β and TNF-α. Conclusions LGG co-association had a negative impact on colonization of P. acnes, and markedly altered the metabolic output and inflammatory response elicited by pathobionts.

Dynamic Alterations of the Gut Microbial Pyrimidine and Purine Metabolism in the Development of Liver Cirrhosis

“…For example, the enriched Bacteroides dorei in our mice with liver cirrhosis contained the thymidine kinase genes involved in thymidine metabolism (Sakanaka et al, 2018). And studies in germ-free mice demonstrated that gut microbiota modulated the metabolism of adenosine (Mager and Burkhard, 2020) and thymidine (Kim et al, 2021). The gut microbiota-derived purine metabolites including eATP and xanthine were related to the development of inflammatory bowel disease (Scott and Gutiérrez-Vázquez, 2021) and high-fat diet-induced obesity (Wei et al, 2021), respectively.…”

Heat‐Treated Adzuki Bean Protein Hydrolysates Reduce Obesity in Mice Fed a High‐Fat Diet via Remodeling Gut Microbiota and Improving Metabolic Function

“…Indole derivatives (indolelactic acid, indoxylsulfuric acid, and 3‐indoleacetic acid) produced by Lactobacillus reduce proinflammatory cytokines and inhibit intestinal inflammation. [ 32 ] Lactobacillus produces glutamate through fermentation, which further generates l ‐glutamine through glutamine synthase. [ 33 ] l ‐glutamine is an important energy source of intestinal mucosa and helps to maintain intestinal health.…”

“…[ 33 ] l ‐glutamine is an important energy source of intestinal mucosa and helps to maintain intestinal health. [ 32 ] Lactobacillus increases the level of N‐acetylated amino acids. [ 32 ] Weight loss is associated with increased N‐acetylaspartate.…”

“…[ 32 ] Lactobacillus increases the level of N‐acetylated amino acids. [ 32 ] Weight loss is associated with increased N‐acetylaspartate. [ 34 ] Lactobacillus also synthesizes carnitine.…”

Effects of Milk Replacer-Based Lactobacillus on Growth and Gut Development of Yaks’ Calves: a Gut Microbiome and Metabolic Study

“…The potential role of certain Lactobacillus rhamnosus GG in regulating gut microbiota modulation and promoting intestinal metabolic profile is accomplished by the increase in beneficial microorganisms. So, the reduction of such microorganisms associated with health threats ( 16 ). Additionally, commensal bacteria in the gut systemically effect the molecules of microbial metabolism, such as short-chain fatty acids ( 17 ).…”