“Bifidobacterium longum?”Here!B. longum (a probiotic strain)

Biotech

Hasn’t appeared in a scanned product yet.

As a supplement

Talk to your doctor or pharmacist.

Roll Call does not check drug interactions or assess personal safety.

A species of Bifidobacterium bacteria naturally found in the human gut, sold as a live-culture probiotic ingredient.

Why it’s used

Taken to support digestive comfort and gut microbiota balance, and sometimes marketed for stress- or mood-related outcomes.

What the evidence says

Some specific B. longum strains have been studied for effects on gut symptoms and, in smaller trials, on stress-related measures, with mixed and strain-specific results. As with other probiotics, the NIH notes that findings for one strain do not generalize to all products labeled with the same species name.

Context

Clinical trials report dosing in colony-forming units, typically in the billions per day, rather than in a mass unit; study duration is usually several weeks.

Rumors

1
Bifidobacterium longum is a 'friendly bacteria' that prevents the growth of harmful bacteria in the stomach and intestines.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- Drugs.com — a publisher: drug information website; owned by Drugsite Limited as trustee of the Drugsite Trust
  How we know who this is
  “Drugs.com is the largest, most widely visited, independent medicine information website available on the Internet.” (their page)
  “The Drugs.com website is owned and operated by Drugsite Limited, as trustee of the Drugsite Trust.” (their page)
2
Bifidobacterium longum causes gas and upset stomach.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- WebMD — a publisher: health information publisher; an Internet Brands company
  How we know who this is
  “As a leader in digital health publishing for more than 25 years, WebMD strives to maintain the most comprehensive and reliable source of health and medical information on the internet.” (their page)
  “© 2005 - 2026 WebMD LLC, an Internet Brands company.” (their page)
3
Bifidobacterium longum improves gut health.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- WebMD — a publisher: health information publisher; an Internet Brands company
  How we know who this is
  “As a leader in digital health publishing for more than 25 years, WebMD strives to maintain the most comprehensive and reliable source of health and medical information on the internet.” (their page)
  “© 2005 - 2026 WebMD LLC, an Internet Brands company.” (their page)
4
Bifidobacterium longum (strain 35624) relieves IBS symptoms such as abdominal discomfort, gas, and bloating.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- Procter & Gamble — a brand: sells Align probiotic products
  How we know who this is
  “© 2026 Procter & Gamble” (their page)
  “ALIGN IS THE #1 MOST RECOMMENDED BRAND BY GASTROENTEROLOGISTS, 5 YEARS IN A ROW.” (their page)
5
Bifidobacterium longum reduces stress, lowers cortisol, and enhances cognitive ability.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- Gene Food — a brand: sells DNA test kits and genetic nutrition reports
  How we know who this is
  “Founded in 2018 by tech entrepreneur John O’Connor, Gene Food is a personalized health company that uses polygenic risk scoring to help people understand how their genetics shape their response to nutrition, environment, and everyday life.” (their page)
  “Gene Food offers DNA test kits through our CLIA-certified lab partner in Houston, TX, and accepts raw data uploads from most major consumer genetic testing platforms.” (their page)