Decreasing Bacteroides Xylanisolvens

In Ian Lipkin et al 2017 study, high Bacteroides Xylanisolvens was reported (on average). [Index to all posts on Study] . “ The human intestine is the only location that Bacteroides xylanivsolvens has been isolated….one of the species involved in breaking down xylan in the human gut, …  and ”Bacteroides fragilis” subspecies A.”[microbewiki]


  • Being considered as a probiotic [2011] – not for CFS/FM/IBS please!
  • ” The investigation of the antibiotic susceptibility indicated that strain DSM 23964 was sensitive to metronidazole, meropenem agents, and clindamycin. Resistance to penicillin and ampicillin was identified to be conferred by the β-lactamase cepA gene… Some of them, like B. xylanisolvens, that are not classified as opportunistic pathogens can be expected to contain strains with a favorable safety profile…his strain may possess immune-modulatory properties and is able to produce short fatty acid chains (propionate, succinate) with potential health-beneficial effects. ” [2011]
  • ” utilised the xylan in different ways, and differently from their use of wheat arabinoxylan.” [2017]
  • “while soy, pulse and nut intake was positively associated with the relative abundance of bacteria related to Bacteroides xylanisolvens.” [2016]
  • ” the metabolic plasticity of B. xylanisolvens towards dietary fibres that contributes to its competitive fitness within the human gut ecosystem” [2016]
  • “The bacteria having a pronounced ability to degrade Alginate, mannuronic acid oligosaccharides and guluronic acid oligosaccharides were isolated from human fecal samples and were identified as Bacteroides ovatus, Bacteroides xylanisolvens, and Bacteroides thetaiotaomicron” [2016]
  • ” In gout, Bacteroides caccae and Bacteroides xylanisolvens are enriched yet Faecalibacterium prausnitzii and Bifidobacterium pseudocatenulatum depleted.” [2016] – This is almost the same pattern as reported by Lipkin (3/4 having the same shift). Gout is  too much uric acid in the blood
    • “Ethanol increases production of uric acid by increasing production of lactic acid, hence lactic acidosis.” [wikipedia]
  • “B. xylanisolvens GH99 reveal the structural basis for binding to D-mannose – rather than D-glucose-configured substrates.”[2015]
  • xylanisolvens XB1A cultured with glucose, xylose or xylans,” [2010]
  • ” bacteria grew well on all the substrates chosen to represent dietary fibres: wheat and corn bran, pea, cabbage and leek fibres, and also on purified xylans.” [2010]
  • “. Xylan and sugars were converted by strain XB1AT mainly into acetate, propionate and succinate.” [2008]


Consumes: xylan, unable to utilize starch or to produce indole

Produces: acetate, propionate, succinate

Bottom Line

Reduce food containing xylan or reduce xylan producing bacteria. Soy. nuts and pulse should be reduced or eliminated.