Yakult – L.Casei Shirota

I have frequently cited this probiotic but have not done an actual post on it. I Today I discovered FDA documentation on it which I have extracted below.

  • “Additionally, L. casei ferments lactic acid from many other precursors. Only the L-enantiomer of lactic acid is formed.” so no d-lactic acid ­čÖé
  • L. casei strain Shirota is 100 percent identical to those of L. casei strains designated ATCC 334 and NCDO 151.”
  • L. casei strain Shirota, like most lactobacilli, is resistant to vancomycin; however, this resistance is not genetically based.”
  • “Yakult describes L. casei strain Shirota as a non-pathogenic and non-toxigenic bacterium.”
  • “ingredient in fermented dairy products at a maximum level of 4×108 colony forming units (cfu) per milliliter (ml).”
  • “The notifier states thatL. casei strain Shirota up to 3.6×1011 cfu/day fed to healthy adults for as long as 5 weeks and to health-compromised adults up to 8×1011 cfu/day for as long as four years, showed no adverse effects.” i.e. 2 liters of Yakult/day

From the alternative names listed above (there are 200+ citations for casei shirota), I found that

  • it produces a”class IId bacteriocin that exhibited antimicrobial activity against some lactobacilli and several Listeria species.”[2013]
  • “cultivation of Lactobacillus casei ATCC 334 in the presence of human intestinal epithelial cells promotes functional changes in bacteria. In particular, the interaction enhanced the immunosuppressive phenotype of L. casei as demonstrated by the ability of L. casei to generate functional regulatory T cells (CD4+CD25+FoxP3+) and production of the anti-inflammatory cytokine interleukin-10 by human peripheral blood mononuclear cells.” [2013]

Impact on CFS:

  • “Decrease in Anxiety symptoms Increase in┬áLactobacillus and┬áBifidobacteria in Fecal samples”[2015] [2009]

It is not effective for IBS but will mitigate some symptoms ┬á(and by inference, only symptom mitigation for CFS) – i.e. reduces inflammation:

  • “After probiotic treatment with LcS, no improvement of 30% in MSS was observed after 8 weeks.” [2016]
  • “Some trials showed a significant improvement of irritable bowel syndrome-related constipation via Lactobacillus casei Shirota” [2005]
  • “There was no significant improvement in the symptom score with probiotic therapy, except for wind (P = 0.04).” [2008]

Similarly, for UC, its impact is again reducing inflammation:

  • “This probiotic-induced improvement in murine chronic inflammatory bowel disease is associated with the down-regulation of pro-inflammatory cytokines such as IL-6 and IFN-gamma production in LPMC. Therefore, LcS may be a useful probiotic for the treatment of human inflammatory bowel disease.” [2005]
  • “probiotic strain Lactobacillus casei Shirota in UC partially restored their normal function indicated by reduced Toll-like receptor 2/4 expression and restoration of their ability to imprint homing molecules on T cells and to generate interleukin-22 production by stimulated T cells.” [2014]

Bottom Line

Yakult has a role in reducing inflammation and potentially to displace some dysfunctional bacteria. It will likely reduce some symptoms.