title: Colonic Fermentation Promotes Decompression sickness in Rats.
abstract: Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body's H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production.
authors: Service de Médecine Hyperbare et Expertise Plongée, HIA Sainte-Anne, BP600, Toulon Cedex 9, France.
authors: Sébastien
authors: S
authors: de Maistre
authors: Équipe Résidente de Recherche Subaquatique Opérationnelle, Institut de Recherche Biomédicale des Armées, BP 600, Toulon Cedex 9, France.
authors: Nicolas
authors: N
authors: Vallée
authors: Service de Médecine Hyperbare et Expertise Plongée, HIA Sainte-Anne, BP600, Toulon Cedex 9, France.
authors: Emmanuel
authors: E
authors: Gempp
authors: Équipe Résidente de Recherche Subaquatique Opérationnelle, Institut de Recherche Biomédicale des Armées, BP 600, Toulon Cedex 9, France.
authors: Kate
authors: K
authors: Lambrechts
authors: Service de Médecine Hyperbare et Expertise Plongée, HIA Sainte-Anne, BP600, Toulon Cedex 9, France.
authors: Pierre
authors: P
authors: Louge
authors: LEHNA, UMR 5023-CNRS/UCBL, Université Claude Bernard Lyon 1, 43 Bd du 11 Novembre 1918, Villeurbanne Cedex, France.
authors: Claude
authors: C
authors: Duchamp
authors: Équipe Résidente de Recherche Subaquatique Opérationnelle, Institut de Recherche Biomédicale des Armées, BP 600, Toulon Cedex 9, France.
authors: Jean-Eric
authors: JE
authors: Blatteau
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D003665:Decompression Sickness / Q000382:microbiology*; D004195:Disease Models, Animal; D005215:Fasting / Q000523:psychology; D005285:Fermentation; D006859:Hydrogen / Q000032:analysis*; D008297:Male; D008353:Mannitol / Q000494:pharmacology*; D051381:Rats; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D008353:Mannitol; D006859:Hydrogen