Reciprocating intestinal flows enhance glucose uptake in C. elegans

Abstract

Despite its physiological and pathological importance, the mechanical relationship between glucose uptake in the intestine and intestinal flows is unclear. In the intestine of the nematode Caenorhabditis elegans, the defecation motor program (DMP) causes reciprocating intestinal flows. Although the DMP is frequently activated in the intestines, its physiological function is unknown. We evaluated the mechanical signature of enhanced glucose uptake by the DMP in worms. Glucose uptake tended to increase with increasing flow velocity during the DMP because of mechanical mixing and transport. However, the increase in input energy required for the DMP was low compared with the calorie intake. The findings suggest that animals with gastrointestinal motility exploit the reciprocating intestinal flows caused by peristalsis to promote nutrient absorption by intestinal cells.

The TWK-26 potassium channel governs nutrient absorption in theC. elegansintestine

“…Lastly, we explored the possibility that twk-26(rhd182[G485E]) may suppress the abnormalities in the DMP exhibited by flr-4 and flr-1 mutants. The DMP is known to promote absorption of glucose in the intestine (Suzuki et al 2022), and mutations in key DMP genes, like flr-1 , restricts fat accumulation (Kaulich et al 2022). Therefore, it is possible that since the twk-26(rhd182) allele suppressed the metabolic phenotypes of the flr-4 and flr-1 mutants, it may also suppress the irregular DMP of these animals; however, activation of TWK-26 did not impact the short DMP interval nor alter the number of intestinal expulsion events that were caused by the flr mutations (Figures 5D-E).…”

“…The C. elegans defecation motor program (DMP) occurs every ∼45 seconds and is coordinated by calcium and proton oscillations in the intestine (Allman et al 2009; Pfeiffer et al 2008). The DMP is coupled to absorption of essential nutrients, including dipeptides, glucose, and lipids (Allman et al 2009; Sheng et al 2015; Suzuki et al 2022). Consistently, mutations that disrupt the DMP (e.g., aex-5 and flr-1 ) reduce somatic intracellular lipid stores (Kaulich et al 2022; Sheng et al 2015), likely due to impaired intestinal acidification and poor nutrient absorption.…”

Arrhythmic Effects Evaluated on Caenorhabditis elegans: The Case of Polypyrrole Nanoparticles

“…elegans exhibits a wide range of pH values from 6 (anterior) to 3 (posterior) (Figure c), similar to humans. Therefore, we measured the stability of Ppy NPs in the pH range 2–13 by DLS using acidic/basic solutions at 0 min and after 20 min since the average residence time within the worm’s intestine is less than 10 min. − Ppy NPs’ size remained constant at all pH values during this period (Figure b), suggesting desirable behavior during exposure to C. elegans.…”

The role of animal hosts in shaping gut microbiome variation

“…In the upper GI regions, this distribution is mainly driven by the acidic conditions (luminal pH < 3), coupled with the high concentrations of host secretions (e.g. antimicrobial effectors, bile acids, pancreatic [5] and dissected guts of adult Drosophila [6], honeybee [7] and Seriola dumerilii [8]. The different gut regions are labelled in each figure.…”