Heavily studied for IBS and its symptoms
Well researched for inflammatory conditions
Shown to help with mood and behavioural issues

Under the microscope: Bifidobacterium infantis 35624
As with many other strains in this database, this bacterial strain has been researched to assess its potential benefits for the relief of Irritable Bowel Syndrome (IBS) and the associated symptoms. The following studies suggest that it may do so because it has an anti-inflammatory effect in the body. It is important to note that this strain is also known by a few different names. This strain has actually recently undergone genome sequencing and whereas it was known beforehand as Bifidobacterium longum subsp. infantis 35624, the genome sequencing has actually caused it to be reclassified as Bifibobacterium longum subsp. longum 35634. Strictly speaking, therefore, this strain should come under the longum species however it is still much better known and commercially sold as an infantis strain, and it has been kept as such for the purpose of this Probiotics Database. This strain is also commercially known as Bifantis® (Altmann F, et al. 2016).
Bifidobacterium infantis 35624 – Safety and Survival
Bifidobacterium infantis 35624 is a food supplement with safety and survivability studies indicating it is able to reach the gut alive and is safe for human consumption. Lynseng-Williamson, K. (2017) produced an assessment of B. infantis 35624 as a food supplement, addressing tolerability across all available clinical trials, concluding ‘a tolerability and safety profile similar to that of placebo’.
A study by Charbonneau, D. et al (2013) found that after 8 weeks of oral supplementation with B. infantis 35624, the strain was recovered from stool samples, suggesting that the strain reaches the gut alive. Faecal levels of Bifidobacterium infantis 35624 were found to decline and return to baseline levels once oral supplementation ceased, indicating its transiency.
Bifidobacterium infantis 35624 and Irritable Bowel Syndrome (IBS)
In a randomised, multiple-dosage, parallel, placebo-controlled, double-blind clinical trial, 75 male and female participants with various presentations of IBS (either constipation, diarrhoea or alternating symptoms) were given either a Lactobacillus salivarius strain or the Bifidobacterium infantis 35624 strain for a period of 8 weeks. Symptoms of IBS were assessed daily. Blood sampling for the measurement of cytokines IL-10 or IL-12 took place at the beginning and end of the study, and these were also compared against the cytokine levels of healthy volunteers. For the individual symptom scores, B. infantis 35624 was associated with a significant reduction in pain/discomfort, bloating/distention, and difficulty passing a bowel movement. Another important finding was that, also following B. infantis 35624 use, cytokine levels in the IBS subjects were similar to the levels in the healthy volunteers, while the levels were not significantly changed in either of the other treatment groups (O’Mahony et al., 2005).

You are here: The 35624 strain is part of the infantis species and the Bifiobacterium genus
Another large scale multicentre, randomised, multiple-dosage, parallel, placebo-controlled, double-blind clinical trial on women was conducted in order to determine the best dosage of Bifidobacterium infantis 35624 for IBS. The trial used 362 female subjects, all aged between18 to 65 years and diagnosed with IBS. The women were randomly split into groups and given one of three different doses of B. infantis 35624: 1 million, 100 million, or ten billion. B. infantis 35624 at the dosage of a hundred million had statistically lower symptom scores at week 4 of the treatment phase for abdominal pain/discomfort, bloating/distention, sense of incomplete evacuation, passage of gas, straining, and bowel habit satisfaction than those receiving placebo (Whorwell et al., 2006).

Graph 1 - B. infantis 35624 reduced symptoms of IBS compared to placebo
A real-world study by Cruchet Munoz et al, (2024) found evidence for the effective use of Bifidobacterium longum 35624 in the management of IBS symptoms in a paediatric population in the presence of a vitamin D deficiency. The single-arm clinical trial aimed to investigate the effects of Bifidobacterium longum 35624 on GI symptoms and baseline vitamin D status in 58 children and adolescents with IBS in Chile. The participants were administered 1 billion colony-forming units of Bifidobacterium longum 35624 each morning with a cold drink for 12 weeks. IBS symptoms were measured at baseline, week 6, week 12 and 2 weeks after the intervention ended. During the 12-week supplementation period, IBS symptoms measures were significantly decreased from baseline. There was a significant decrease in abdominal pain frequency, abdominal pain severity, abdominal distension severity and impact on life, and a significant increase in bowel habit satisfaction. An important finding was that throughout the study periods there was no association between IBS symptoms and Vitamin D status. Future well-designed studies in a larger cohort are necessary to confirm the findings.
Further relevant studies: Bairead et al (2005), Brenner (2009a), Brenner et al (2009b), Chang et al (2005), Charbonneau et al., (2005a), Charbonneau et al., (2005b), Charbonneau et al., (2005c), Charbonneau et al., (2005d), Chen K-S et al (2005), Mayer (2008), O’Mahony et al., (2005), Quigley et al (2005a), Quigley et al (2005b), Sabaté J.M., & Iglicki F. (2022).
Bifidobacterium infantis 35624 and Inflammatory Conditions - Ulcerative Colitis, Chronic Fatigue Syndrome and Psoriasis
In a study authored by Konieczna (2012), cytokine secretion and T cell expression were monitored in individuals who were given Bifidobacterium infantis 35624. It was found that B. infantis administration in humans promotes immuno-regulatory responses, suggesting that this microbe may have therapeutic utility in patients with inflammatory disease. These findings link nutrition, gut microbiota and the induction of tolerance within the gastrointestinal mucosa.
Bifidobacterium infantis 35624 was also found to modulate inflammatory processes beyond the gut. Groeger et al (2013) assessed the impact of oral administration of B. infantis 35624, for 6‒8 weeks on inflammatory biomarker and plasma cytokine levels in patients with ulcerative colitis, chronic fatigue syndrome and psoriasis in three separate randomised, double-blind, placebo-controlled interventions. In addition to this, the effect of B. infantis 35624 on immunological biomarkers in healthy subjects was assessed. This strain of bacteria resulted in a reduced plasma CRP levels in all three inflammatory disorders. Compared with the placebo results, additionally plasma TNF-α was reduced in chronic fatigue syndrome and psoriasis, while IL-6 was reduced in ulcerative colitis and chronic fatigue syndrome. These results show the ability of this microbe to reduce pro-inflammatory markers both in the gut and systemically.
Further relevant studies: Gad et al., (2011), Johnson et al., (2011), Konieczna et al., (2013), Scully et al (2013) Symonds et al., (2012), van der Kleij et al., (2008), O’Mahony et al., (2005), Sheil et al (2007), Shanahan et al (2006), Sommerfield et al (2003), Symonds et al (2007), Wall et al (2010), von Wright et al (2002).
Bifidobacterium infantis 35624 and Mood
This strain has been used in rat studies conducted by Desbonnet et al., (2008) (2010), to assess the effects of probiotics on behaviour and mood. Results suggested that probiotic treatment resulted in normalisation of the immune response, reversal of behavioural issues and reduction in depressive symptoms.
Bifidobacterium infantis 35624 and Inflammation
In the same O’Mahony et al (2005) trial that is described in the IBS section above, it was found that the ratio of anti-inflammatory to pro-inflammatory cytokines in the gut was normalised. This suggests an immune-modulating role for this microorganism, in this disorder.
Further relevant studies: Davies et al (2009), McCarthy et al (2003), O’Callaghan et al (2002), O’Callaghan et al (2003), O’Callaghan et al (2004), O’Mahony et al (2008), O’Mahony et al (2005), O’Mahony et al (2006), Sheil et al.(2006a), Sheil et al., (2006b) Shilling et al., (2005), Sibartie et al., (2009).
Bifidobacterium infantis 35624 and Other Digestive Symptoms and Infections
A pilot study by Frech et al (2011) indicated a role for probiotics to support systemic sclerosis (SSc) patients with systemic sclerosis-associated re-flux and distention/ bloating symptoms. Improvements in symptoms and total gastrointestinal tract (GIT) disease scales were noted.
Some protection against Salmonella infection and its damaging effects were noted in a variety of murine studies - O’Mahony et al., (2002), O’Mahony et al., (2004), O'Hara et al, (2006), Sommerfield et al., (2005).
Authors: Information on this strain was gathered by Joanna Scott-Lutyens BA (hons), DipION, Nutritional Therapist; and Kerry Beeson, BSc (Nut.Med) Nutritional Therapist.
As some properties & benefits of probiotics may be strain-specific, this database provides even more detailed information at strain level. Read more about the strains that we have included from this genus below.
Bifidobacterium lactis strains: Bifidobacterium lactis Bi-07®, Bifidobacterium lactis BB-12®, Bifidobacterium lactis Bl-04®.
Bifidobacterium infantis strains: Bifidobacterium infantis 35624.
Bifidobacterium breve strains: Bifidobacterium breve M-16V®.
