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What Foods Are High in Lactobacillus? Fermented Foods by Species
In this article
Lactobacillus species are found in live fermented foods: yoghurt and kefir, raw sauerkraut and kimchi, brine-fermented pickles and olives, some cheeses, and a sourdough starter before it is baked. Fresh fruit carries too few wild lactic acid bacteria to count as a source, and anything pasteurised, baked or cooked after fermenting has lost its live cultures. Which species, and how many, depends on the food and the batch, and most labels do not say. This page is one spoke of the Wellgard probiotics guide.
Evidence at a glance
- Trials: one randomised diet study (36 adults, 17 weeks), one systematic review of kefir (16 trials), one pooled analysis of 12 trials (1,499 people) and one stool-tracking study (117 people).
- Largest single trial: 117 people, 8 weeks of daily dosing with one bifidobacterium strain.
- Strongest measured outcome: antibiotic-associated diarrhoea fell from 22.4% to 12.3% with one Lactobacillus rhamnosus strain across 11 trials of 1,308 people.
- What no trial we found has tested: what eating one Lactobacillus-rich food does to the lactobacilli in a person's gut.
Sources checked on 12 October 2026.
What foods are high in Lactobacillus?
The foods that carry lactobacilli are the ones still alive when you eat them: yoghurt with live cultures, kefir, raw sauerkraut and kimchi, brine-fermented pickles and olives, some aged and soft cheeses, and a sourdough starter. The 2021 expert consensus defines a fermented food as one made through desired microbial growth and separates it from a defined live-culture product.1
| Food | Lactobacilli usually reported | Live on a UK shelf? |
|---|---|---|
| Yoghurt | L. delbrueckii subsp. bulgaricus as a starter; L. acidophilus often added | Yes, unless heat-treated after fermenting; the label says "live cultures" |
| Kefir | Several lactobacilli alongside yeasts; the grain decides (see drinks with live cultures) | Chilled kefir yes; some ambient drinks are pasteurised |
| Sauerkraut and kimchi | L. plantarum and L. brevis dominate a vegetable ferment | Raw chilled jars yes; shelf-stable jars are usually pasteurised |
| Cheese | L. helveticus, L. casei and L. paracasei in some aged and soft cheeses | Many aged and unpasteurised cheeses yes; processed cheese no |
| Sourdough starter | L. sanfranciscensis and related species | The starter yes; the baked loaf no |
| Olives and brine pickles | L. plantarum in brine-fermented, not vinegar, products | Only brine-fermented chilled products |
| Miso and tempeh | Lactobacilli take part in the ferment | Usually pasteurised, cooked or heated before eating |
Yoghurt is the one food with an authorised live-culture claim in Great Britain: its starter cultures "improve lactose digestion of the product in individuals who have difficulty digesting lactose", a claim conditioned on at least 100 million live starter cells per gram of the yoghurt, not on a capsule.2 Lactobacillus reuteri has its own list: foods with Lactobacillus reuteri.
What is Lactobacillus?
Lactobacillus is a group of lactic acid bacteria that live in fermented foods and in people, including the gut and the vagina; some are sold as live cultures in yoghurts and supplements. In 2020 the genus, then 261 species, was split into 25 genera on whole-genome sequencing, so L. plantarum is now Lactiplantibacillus plantarum, L. rhamnosus is Lacticaseibacillus rhamnosus and L. reuteri is Limosilactobacillus reuteri, while L. acidophilus and L. crispatus kept their names. "Lactobacilli" remains the group word, and labels and papers use both names side by side.3 The NHS describes probiotics as "live bacteria and yeasts" that are "usually added to yoghurts or taken as food supplements".4 Four species in brief:
- Lactobacillus acidophilus was first isolated from the human gut and named in 1900; what acidophilus is good for has its trials.5
- Lactobacillus crispatus is one of four lactobacilli that each dominated a type of vaginal community in a study of 396 women.6
- Lactobacillus reuteri is found in the human gut, urinary tract, skin and breast milk; what Lactobacillus reuteri does has more.7
- Lactobacillus rhamnosus is found in the human gut and in dairy foods such as cheese.8
More on the genus: what Lactobacillus is and whether it causes disease.
Which foods do not contain Lactobacillus?
Fresh fruit is not a source. Lactic acid bacteria are only a small part of the wild microbes on fruit and vegetables; they matter when produce is left to ferment, not in a fresh apple.9 Bananas, apples, watermelon and grapefruit are often listed online as Lactobacillus foods, but the papers on "probiotic fruit" are about adding cultures to juices. What fruit carries is fibre: food for the bacteria already there, not a source of new ones. Also off the list: vinegar pickles and anything pasteurised, baked or boiled after fermenting, because a food carries live cultures only if nothing has killed them since.1
How do you get Lactobacillus?
From live fermented foods, eaten regularly, because the lactobacilli in them pass through rather than settle. In the one randomised diet study, from 2021, 36 healthy adults followed a high-fermented-food diet or a high-fibre diet for 17 weeks. The fermented-food diet "steadily increased microbiota diversity and decreased inflammatory markers"; the high-fibre diet did not change diversity, and its primary immune outcome was unchanged.10 It is one small study. Kefir had 16 randomised trials in a 2023 systematic review; 12 were at high risk of bias, and the authors said no recommendation could be made until better trials exist.11
How to increase Lactobacillus in your body?
There is no home test and no recognised deficiency state for Lactobacillus, so the practical target is the habit itself. In a study that tracked one bifidobacterium strain in 117 people for eight weeks, stool levels rose during dosing and "approached baseline once dosing ceased"; continuous intake was needed to keep them steady.12 No study we found has tracked sauerkraut's lactobacilli this way, but the capsule result suggests they too pass through rather than settle.
Food or supplement: what is the difference?
A jar of sauerkraut names no strains or amounts, while a live-culture capsule states its species and count; the trials used capsules, and this page does not rank the two. In a 2015 pooled analysis of 12 randomised trials (1,499 people), one Lactobacillus rhamnosus strain taken during an antibiotic course reduced antibiotic-associated diarrhoea from 22.4% to 12.3% in the 11 trials reporting it (1,308 people; relative risk 0.49); the difference was significant in children (RR 0.48) and not significant in adults as a group.13
Who should take care is the same for food and capsule. Across 36 antibiotic trials (9,312 adults), adverse events were no more common on live cultures than on placebo (RR 1.00).14 A few case reports describe bloodstream infections in people with a weakened immune system, people seriously ill or in hospital with a central line, and premature babies; anyone in those groups, or whose doctor has said so, asks their clinical team first. In a 2021 Cochrane review of trials that gave live cultures in pregnancy to lower the chance of gestational diabetes, pre-eclampsia was more common in the women who took them, so speak to a midwife or GP before any supplement in pregnancy.15 The NHS page, last reviewed 24 November 2022 and past its own review date, says "there's little evidence to support many health claims made about them".4
What we don't know
- No trial we found has measured whether eating a named fermented food raises the lactobacilli in a person's gut, or for how long.
- No survey has compared the Lactobacillus content of supermarket yoghurts, kefirs or sauerkrauts batch by batch.
- No larger trial has repeated the 2021 diet study of 36 people, and none in people with a diagnosed gut condition.
Frequently asked questions
What happens when you have no Lactobacillus?
In the gut, no such state has been described in healthy adults, and there is no test or diagnosis for a shortage of lactobacilli. The vagina is different, because lactobacilli usually dominate there; see what intimate flora is for what their absence means.
What happens if you have too much Lactobacillus?
From food, there is no record of harm in healthy people. The rare cases of lactobacilli in the bloodstream come from seriously ill people: in a Finnish series of 89 cases, 82% had severe or fatal underlying disease, and the predisposing factors were immunosuppression, long hospital stays and surgery.16
Does cooking kill Lactobacillus?
Yes. Baking, boiling and pasteurisation kill live cultures, which is why a baked loaf, cooked tempeh, boiled miso and a pasteurised jar are not sources.
Sources
- Marco ML, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nature Reviews Gastroenterology & Hepatology, 2021. Expert consensus statement. PubMed 33398112.
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific opinion on live yoghurt cultures and improved lactose digestion. EFSA Journal, 2010. Regulatory opinion. doi:10.2903/j.efsa.2010.1763.
- Zheng J, et al. A taxonomic note on the genus Lactobacillus: description of 23 novel genera, emended description of the genus Lactobacillus Beijerinck 1901, and union of Lactobacillaceae and Leuconostocaceae. International Journal of Systematic and Evolutionary Microbiology, 2020. Taxonomic study, 261 species. PubMed 32293557.
- NHS. Probiotics. nhs.uk/conditions/probiotics. Page last reviewed 24 November 2022; next review due 24 November 2025 (review overdue).
- Bull M, et al. FEMS Microbiology Letters, 2013. Narrative review of the history and taxonomy of Lactobacillus acidophilus. PubMed 24152174.
- Ravel J, et al. Proceedings of the National Academy of Sciences, 2011. Observational, 396 women. PubMed 20534435.
- Mu Q, et al. Frontiers in Microbiology, 2018. Narrative review of Lactobacillus reuteri. PubMed 29725324.
- You L, et al. Food Research International, 2023. Comparative genomics study of Lacticaseibacillus rhamnosus, 384 genomes. PubMed 37803772.
- Di Cagno R, et al. Exploitation of vegetables and fruits through lactic acid fermentation. Food Microbiology, 2013. Narrative review. PubMed 23122495.
- Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021. Randomised trial, 36 adults, 17 weeks. PubMed 34256014.
- Kairey L, et al. The effects of kefir consumption on human health: a systematic review of randomized controlled trials. Nutrition Reviews, 2023. Systematic review, 16 trials. PubMed 35913411.
- Charbonneau D, et al. Gut Microbes, 2013. Placebo-controlled stool-tracking study of one Bifidobacterium infantis strain, 117 people, 8 weeks. PubMed 23549409.
- Szajewska H, Kołodziej M. Alimentary Pharmacology & Therapeutics, 2015. Pooled analysis of one Lactobacillus rhamnosus strain and antibiotic-associated diarrhoea, 12 trials, 1,499 people. PubMed 26365389.
- Liao W, et al. Probiotics for the prevention of antibiotic-associated diarrhea in adults: a meta-analysis of randomized placebo-controlled trials. Journal of Clinical Gastroenterology, 2021. Pooled analysis, 36 trials, 9,312 adults. PubMed 33234881.
- Davidson SJ, et al. Cochrane Database of Systematic Reviews, 2021. Cochrane review of live cultures given in pregnancy and gestational diabetes outcomes, 7 trials, 1,647 women. PubMed 33870484.
- Salminen MK, et al. Clinical Infectious Diseases, 2004. Case series of Lactobacillus bloodstream infections, 89 people. PubMed 14679449.
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