Biology subjects

Bindels, L. B.

Publications and source records attributed to Bindels, L. B..

3 recordsLinked to original sources

bioRxiv2026

Mixed acid fermentation products from Lachnospira eligens counteract myotube atrophy

IntroductionAcute myeloid leukemia (AML) is a hematological malignancy associated with muscle wasting. As the relative abundance of Lachnospira eligens was reduced in patients with AML compared to healthy individuals and correlated positively with muscle strength, we hypothesized that L. eligens positively impacts the muscle through the production of small metabolites reaching the systemic circulation. MethodsL. eligens levels were analyzed in two additional independent cohorts. Six L. eligens isolates were characterized through whole-genome sequencing to select clinically relevant strains. The composition of their culture supernatant was analyzed by metabolomics. The impact of L. eligens supernatant on dexamethasone- and interleukin-6-atrophied murine myotubes was assessed. Bioactive metabolites and their production mechanism were identified using among others bioactivity-guided fractionation. The underlying mechanism was also explored on the host side through myotubes transcriptome analysis and metabolic flux analysis. The relevance of bioactive metabolites and their production mechanism was evaluated through clinical data and samples analyses and in a mouse model of leukemia. ResultsThe levels of L. eligens are reduced in independent cohorts of patients with AML and its supernatant counteracts myotube atrophy. This anti-atrophic effect, conserved between strains of the same species, depends on the occurrence of mixed acid fermentation (MAF) in anoxic culture conditions and the presence of its acid end-products acetate, formate and D-lactate. Consistent with those results, blood levels of acetate are decreased and the relative abundance of fecal bacteria capable of performing aerobic respiration is increased in patients with AML. However, bacterial supernatant failed to prevent muscle atrophy and weakness in leukemic mice, likely due to insufficient sustained elevation of acid end-products in the blood. ConclusionThis work reveals the anti-atrophic effect of MAF end-products on myotubes and suggests the importance of considering gut electron acceptor levels (e.g. O2) in disorders affecting muscle health. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/729780v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@112529eorg.highwire.dtl.DTLVardef@1ee1929org.highwire.dtl.DTLVardef@b5f389org.highwire.dtl.DTLVardef@187bc40_HPS_FORMAT_FIGEXP M_FIG Mixed acid fermentation products from Lachnospira eligens counteract myotube atrophy. Our study suggests that gut anaerobiosis is disrupted in treatment-naive patients with acute myeloid leukemia (AML), leading to decreased circulating acetate levels and a reduced relative abundance of L. eligens, which significantly correlated with muscle strength. In line with this framework, in vitro experiments demonstrate that the culture supernatant of L. eligens, which contains mixed acid fermentation (MAF) end-products such as acetate, effectively counteracts C2C12 myotube atrophy in the presence of pro-atrophying stimuli. Further mechanistic experiments indicate a causal role for MAF end-products in this anti-atrophying effect. Created with BioRender.com. Legend: solid frames: experimental results; dashed frames: hypothetical conclusions derived from results; black solid arrow: established correlation; black dashed arrows: hypothetical causation. C_FIG

microbiology↗

bioRxiv2025

Characterisation of changes in the gut microbiota associated with eating disorders

BackgroundEating disorders are serious pathologies that often begin in adolescence or young adulthood and persist for a significant period of time, with a strong negative impact on patients quality of life and mortality. The etiological origins of eating disorders are complex and involve both biological, psychological and societal factors. The gut microbiota was recently proposed as one of the potential factors involved in eating disorders. To gain a better understanding of the potential role of the gut microbiota in these diseases, we used 16S rRNA sequencing to compare the composition of the faecal microbiota of patients with all typical forms of eating disorders, i.e. anorexia nervosa, bulimia nervosa or binge-eating disorder, with that of healthy individuals. ResultsOur results demonstrate that each type of eating disorder is associated with a specific gut bacterial signature. We observed, for example, a decrease in the relative abundances of Agathobacter and Romboutsia genera and an increase in Pseudomonas in patients with anorexia, while patients with binge-eating disorder exhibit a decrease in the relative abundances of Akkermansia and Intestinimonas and an increase in Streptococcus, Eggerthella and Proteus. We also highlight a heterogeneity of gut microbiota composition in different subcategories of eating disorders, such as restricting versus binge-purge type anorexia or typical versus atypical binge-eating disorder. By focusing on the comorbidities reported by patients, we finally identified several bacterial taxa, such as Acidaminococcus and Eggerthella, whose level correlates with the occurrence of anxiety or depressive-like symptoms. ConclusionsTogether, our work demonstrates that eating disorders are associated with specific changes in gut microbiota composition and highlight the necessity to finely stratify patients to identify robust microbial signatures. In addition, we identified bacterial taxa correlating with comorbidities and decreased quality of life reported by patients. Our results now pave the way for determining the predictive value of the abundance of these taxa on the duration of the pathology or on the likelihood of relapse. They also constitute a valuable resource to further demonstrate the causal role of the gut microbiota in the onset or chronicisation of eating disorders.

microbiology↗

bioRxiv2017

A gut pathobiont synergizes with the microbiota to instigate inflammatory disease marked by immunoreactivity against other symbionts but not itself

Inflammatory bowel diseases (IBD) are likely driven by aberrant immune responses directed against the resident microbiota. Although IBD is commonly associated with a dysbiotic microbiota enriched in putative pathobionts, the etiological agents of IBD remain unknown. Using a pathobiont-induced intestinal inflammation model and a defined bacterial community, we provide new insights into the immune-microbiota interactions during disease. In our model system, the pathobiont Helicobacter bilis instigates disease following sub-pathological dextran sulfate sodium treatment. We show that H. bilis causes mild inflammation in mono-associated mice, but severe disease in the presence of a microbiota, demonstrating synergy between the pathobiont and microbiota in exacerbating pathology. Remarkably, inflammation depends on the presence of H. bilis, but is marked by a predominant Th17 response against specific members of the microbiota and not the pathobiont, even upon the removal of the most immune-dominant taxa. Neither increases in pathobiont burden nor unique changes in immune-targeted microbiota member abundances are observed during disease. Collectively, our findings demonstrate that a pathobiont instigates inflammation without being the primary target of a Th17 response or by altering the microbiota community structure. Moreover, our findings point toward monitoring pathobiont-induced changes in microbiota immune targeting as a new concept in IBD diagnotics.

immunology↗