Biology subjects

Randuineau, G.

Publications and source records attributed to Randuineau, G..

3 recordsLinked to original sources

bioRxiv2025

Human milk bacteria assembled into functionally distinct synthetic communities in infant formula differently affect intestinal physiology and microbiota in neonatal mini-piglets

The contribution of Human milk (HM) microbiota to infant gut health was addressed by evaluating the impact of HM bacteria, combined in two synthetic communities (SynComs) exhibiting anti-inflammatory (AI) or high immunomodulatory (HI) properties in vitro, on gut immune and barrier functions, and microbiota. Neonatal mini-piglets were fed either a formula without supplementation (CTRL) or supplemented with AI or HI SynComs, and were compared to sow milk-fed (SM) piglets over a period of 24 days. Feces were collected on postnatal day (PND) 8, and ileal, colonic and fecal samples were collected on PND24. The multifactorial analysis indicated that the two HM-derived SynComs impacted microbiota and intestinal functions differently. Several genera, mainly belonging to Bacillota, displayed different relative abundances between the formula-fed groups at both PND8 and PND24. At PND8, the fecal sIgA level in HI piglets was slightly lower than in SM piglets but markedly higher than in CTRL and AI piglets. SynComs HI and/or AI slightly increased the expression of genes involved in pro-inflammatory (IL6, TNFaR1), antioxidant (SOD2), anti-inflammatory (SOCS3) and Treg (FOXP3) pathways in ileal and colonic tissues compared with the CTRL group. Systemic immune functions were also modulated with a cytokine secretion capacity of peripheral blood mononuclear cells that tended to be higher with HI supplementation. Interestingly, SynCom bacteria were correlated with several ileal and colonic genera, and both were correlated with physiological variables. Overall, our findings support the influence of HM bacteria, provided in formulas as SynCom at a physiological concentration, on gut microbiota and functions. ImportanceEarly-life environmental factors, such as neonatal diet, influence the gut microbiota, which plays a key role in the functional development of the gut. However, the role of the human milk (HM) microbiota, particularly with regard to the immunomodulatory properties of HM bacteria, is not well understood. This study investigates the differential effects of two synthetic communities with a similar taxonomic composition representative of the taxonomic diversity of the HM microbiota. Thse communities exhibit contrasting immunomodulatory properties that were previously characterized using an in vitro intestinal quadricellular model. Daily supplementation with these two SynComs modulated the composition of the gut microbiota and the gut physiology differently, particularly the intestinal immune signatures. In conclusion, the functional profile of bacteria within the HM microbiota may induce distinct developmental profiles of gut physiology in infants.

physiology↗

bioRxiv2024

Yo-yo dieting deregulates feeding behavior in mice via the induction of durable gut dysbiosis

Background & AimsAlternating periods of excessive and restrained eating results in weight cycling, a known risk factor for eating behavior dysregulation such as binge eating. Diet alternation also induces changes in intestinal microbiota composition. We tested the hypothesis that recurrent diet alternation alters hedonic feeding regulation by changing either or both intestinal microbiota and brain homeostasis in mouse. MethodsC57BL/6 mice underwent 3 cycles of 1 week of western diet (WD, 45% kcal from fat) separated by 2 weeks of chow diet (CYCL group) or staid under chow diet (CTRL group). Food intake was monitored after each dietary change. Striatum, hypothalamus, brainstem and caecal content were collected before the third WD introduction in CYCL mice and in CTRL mice. Microbiota transfer from CYCL or CTRL mice into naive recipient mice was performed to investigate whether gut microbiota per se could explain differences in eating behavior during weight cycling. ResultsDiet alternation in CYCL mice resulted in weight cycling, with enhanced weight gain upon each WD feeding phase. CYCL mice increased their energy intake specifically during the first hours following WD re-introduction, reminiscent of binge-eating episodes. Expression of reward-related genes in the striatum and thickness of the astro-glial barrier in the brain stem were enhanced in CYCL compared to CTRL mice. Diet alternation also induced caecal dysbiosis in CYCL mice. Gut microbiota transfer from CYCL mice to naive recipient mice recapitulated the altered eating behavior upon WD exposure. ConclusionsAlternation between high-energy and standard diet durably remodels the gut microbiota and the brain towards a profile associated with an increase in hedonic appetite. Using gut microbiota transfer, we established that this microbiota signature affects hedonic feeding regulation. These results open the ways to microbiota-targeted strategies to prevent development of eating disorders in weight cycling patients.

physiology↗

bioRxiv2024

Initial pig developmental stage influences intestinal organoid growth but not phenotype

Intestinal organoids are promising tools in the context of animal experiment reduction. Yet, a thorough characterization of the impact of the origin of intestinal stem cells (ISC) on organoid phenotype is needed to routinely use this cellular model. Our objective was to evaluate the effect of ISC donor age on the growth, morphology and cellular composition of intestinal organoids derived from pig, a valuable model of Humans. Organoids were derived from jejunal and colonic ISC obtained from 1, 7, 28, 36 and 180-day old pigs and passaged three times. We first confirmed by qPCR that the expression of 18% of the >80 studied genes related to various intestinal functions differed between jejunal and colonic organoids after two passages (P<0.05). Growth and morphology of organoids depended on intestinal location (greater number and larger organoids derived from colonic than jejunal ISC, P<0.05) but also pig age. Indeed, when ISC were derived from young piglets, the ratio of organoids to spheroids was greater (P<0.05), spheroids were larger during the primary culture but smaller after two passages (P<0.05) and organoids smaller after one passage (P>0.05) compared to ISC from older pigs. Finally, no difference in cellular composition, evaluated by immunostaining of markers of the major intestinal cell types (absorptive, enteroendocrine and goblet cells) were observed between organoids originating from 7 or 180-day old pigs, while difference between intestinal site origin were noticed. In conclusion, while the age of the tissue donor affected organoid growth and morphology, it did not influence their phenotype.

physiology↗