Table of ContentsView AllTable of ContentsCan They Prevent Illness?Gut Health & ImmunityBest Probiotics for ImmunityHow Long for Results?Who Should Avoid Them?Natural Probiotics

Table of ContentsView All

View All

Table of Contents

Can They Prevent Illness?

Gut Health & Immunity

Best Probiotics for Immunity

How Long for Results?

Who Should Avoid Them?

Natural Probiotics

Nearly 1,000 species of bacteria and microorganisms make up the gut microbiome.Some scientific evidence supports the connection between gut microbiome health and immunity—both local to the gut (stomach, intestines, and colon) and system-wide.Probiotics feed the gut microbiome health bacteria and may play a key role in supporting the gut-immunity link and helpboost immune health.Can Probiotics Keep You From Getting Sick?While probiotics cannot prevent illness, one systematic review examining research on probiotics and immunity found they may help shorten the length of colds and severity of cold symptoms.These immune system benefits are due to their effect on cells and beneficial colonies of bacteria and viruses in the gut.Certain probiotics stimulate dendritic cells in the intestines, which trigger and modulate immune system activity, supporting immune health.A separate literature review study found that probiotics may help improve the effectiveness of the influenza (flu) vaccine in preventing illness.Researchers have noted positive effects for various intestinal diseases, noting that when taken along with antibiotics, probiotics may help with diarrhea and managingClostridioides difficile(C. diff) infection, a bacterial infection affecting the gut.While these results hold promise for immune health and managing gastrointestinal (GI) illnesses, more research is needed to validate these theories.What Are Probiotics?Probioticsare microorganisms—typically bacteria or fungi (yeasts)—that support gut health and the body’s immune response. The most common types areLactobacillusandBifidobacteriumbacteria and the yeastSaccharomyces boulardii.Common sources of probiotics are fermented foods (kimchi, sauerkraut), yogurt, and dietary supplements.The Gut Health and Immune System LinkBetween 70% and 80% of the body’s immune cells are found in the gut, showing an intimate link between gut health and immune function.Gut health influences inflammation, which is the body’s immune response and a characteristic of infections or diseases.In one study, researchers found that an irregular immune response to the gut microbiome was at the root ofinflammatory bowel disease(IBD).Further, a healthy gut microbiome helps prevent the growth of dangerous, disease-causing bacterial strains like C. diff.Which Probiotics Are Best for the Immune System?A wide range of bacteria and yeasts are considered probiotics. Those most known to benefit the immune system are:AcidophilusLactobacilluscaseiLactobacillus paracaseiLactobacillus helveticusLactobacillus rhamnosusBifidobacterium bifidumBifidobacterium longumHow Long Does It Take Probiotics to Work in Your Immune System?The timing of results can vary based on the specific type of probiotic you use and your desired results (e.g., reducing GI symptoms or other systemic issues).Probiotics may reduce symptoms associated with illness. For example, researchers found that probiotics used along with other therapies reduced the duration of diarrhea symptoms in children from eight or nine days to about four.A study comparing 12 weeks of probiotics vs.placebo(a substance with no therapeutic effect) for upper respiratory infections of these infections. When they did get sick, symptoms were less severe and did not last as long as those in the placebo group.When Can You Expect Results?Taking probiotics won’t immediately improve your immune health. Depending on the type of probiotic you use, it can take from several weeks to three months or more of daily use to see positive effects.Who Should Not Take Probiotics?Because probiotics are live microorganisms, taking them is not without risk. Rarely, they can cause infection, toxicity, andantibiotic resistance(antibiotics failing to work). While generally safe for healthy adults, foods or supplements probiotics may be dangerous for the following populations:People with weakened immune systemsPeople with severe or chronic illnessesInfants, especially those born prematurelyPregnant people, especially those in the last trimesterBefore starting a probiotic regimen, talk to a healthcare provider about the potential benefits and drawbacks. They may be able to advise you on dosages and the type to take.Other Natural Probiotic SourcesThough many supplements contain probiotics, these microorganisms are naturally occurring and found in a range ofnatural (and often fermented) food sources, such as:Buttermilk, fermented milk productsCertain cheeses, including raw or aged cheddar, Swiss cheese, and GoudaKefirKimchiKombuchaMisoPickled cucumber, beets, carrots, or other foodsSauerkrautSourdough breadSome food products contain supplemental probiotics. It’s important toread nutrition facts labelsand understand the foods you consume.SummaryProbiotics are microorganisms—typically bacteria and yeasts—that may support immune health. They occur naturally in fermented foods like yogurt and sauerkraut, or you can take them in supplement form to support the gut microbiome. Though more research is needed, there’s evidence that taking probiotics can help boost immunity and prevent illness.

Nearly 1,000 species of bacteria and microorganisms make up the gut microbiome.Some scientific evidence supports the connection between gut microbiome health and immunity—both local to the gut (stomach, intestines, and colon) and system-wide.

Probiotics feed the gut microbiome health bacteria and may play a key role in supporting the gut-immunity link and helpboost immune health.

Can Probiotics Keep You From Getting Sick?

While probiotics cannot prevent illness, one systematic review examining research on probiotics and immunity found they may help shorten the length of colds and severity of cold symptoms.

These immune system benefits are due to their effect on cells and beneficial colonies of bacteria and viruses in the gut.Certain probiotics stimulate dendritic cells in the intestines, which trigger and modulate immune system activity, supporting immune health.

A separate literature review study found that probiotics may help improve the effectiveness of the influenza (flu) vaccine in preventing illness.

Researchers have noted positive effects for various intestinal diseases, noting that when taken along with antibiotics, probiotics may help with diarrhea and managingClostridioides difficile(C. diff) infection, a bacterial infection affecting the gut.

While these results hold promise for immune health and managing gastrointestinal (GI) illnesses, more research is needed to validate these theories.

What Are Probiotics?Probioticsare microorganisms—typically bacteria or fungi (yeasts)—that support gut health and the body’s immune response. The most common types areLactobacillusandBifidobacteriumbacteria and the yeastSaccharomyces boulardii.Common sources of probiotics are fermented foods (kimchi, sauerkraut), yogurt, and dietary supplements.

What Are Probiotics?

Probioticsare microorganisms—typically bacteria or fungi (yeasts)—that support gut health and the body’s immune response. The most common types areLactobacillusandBifidobacteriumbacteria and the yeastSaccharomyces boulardii.Common sources of probiotics are fermented foods (kimchi, sauerkraut), yogurt, and dietary supplements.

Between 70% and 80% of the body’s immune cells are found in the gut, showing an intimate link between gut health and immune function.Gut health influences inflammation, which is the body’s immune response and a characteristic of infections or diseases.

In one study, researchers found that an irregular immune response to the gut microbiome was at the root ofinflammatory bowel disease(IBD).Further, a healthy gut microbiome helps prevent the growth of dangerous, disease-causing bacterial strains like C. diff.

Which Probiotics Are Best for the Immune System?

A wide range of bacteria and yeasts are considered probiotics. Those most known to benefit the immune system are:

How Long Does It Take Probiotics to Work in Your Immune System?

The timing of results can vary based on the specific type of probiotic you use and your desired results (e.g., reducing GI symptoms or other systemic issues).

Probiotics may reduce symptoms associated with illness. For example, researchers found that probiotics used along with other therapies reduced the duration of diarrhea symptoms in children from eight or nine days to about four.

A study comparing 12 weeks of probiotics vs.placebo(a substance with no therapeutic effect) for upper respiratory infections of these infections. When they did get sick, symptoms were less severe and did not last as long as those in the placebo group.

When Can You Expect Results?Taking probiotics won’t immediately improve your immune health. Depending on the type of probiotic you use, it can take from several weeks to three months or more of daily use to see positive effects.

When Can You Expect Results?

Taking probiotics won’t immediately improve your immune health. Depending on the type of probiotic you use, it can take from several weeks to three months or more of daily use to see positive effects.

Who Should Not Take Probiotics?

Because probiotics are live microorganisms, taking them is not without risk. Rarely, they can cause infection, toxicity, andantibiotic resistance(antibiotics failing to work). While generally safe for healthy adults, foods or supplements probiotics may be dangerous for the following populations:

Before starting a probiotic regimen, talk to a healthcare provider about the potential benefits and drawbacks. They may be able to advise you on dosages and the type to take.

Other Natural Probiotic Sources

Though many supplements contain probiotics, these microorganisms are naturally occurring and found in a range ofnatural (and often fermented) food sources, such as:

Some food products contain supplemental probiotics. It’s important toread nutrition facts labelsand understand the foods you consume.

Summary

Probiotics are microorganisms—typically bacteria and yeasts—that may support immune health. They occur naturally in fermented foods like yogurt and sauerkraut, or you can take them in supplement form to support the gut microbiome. Though more research is needed, there’s evidence that taking probiotics can help boost immunity and prevent illness.

11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB.Impacts of gut bacteria on human health and diseases.Int J Mol Sci. 2015;16(4):7493-7519. doi:10.3390/ijms16047493Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ.The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies.Nutrients. 2021;13(3):886. doi:10.3390/nu13030886Khalesi S, Bellissimo N, Vandelanotte C, Williams S, Stanley D, Irwin C.A review of probiotic supplementation in healthy adults: helpful or hype?Eur J Clin Nutr. 2019;73(1):24-37. doi:10.1038/s41430-018-0135-9King S, Glanville J, Sanders ME, Fitzgerald A, Varley D.Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis.Br J Nutr. 2014;112(1):41-54. doi:10.1017/S0007114514000075Peroni DG, Morelli L.Probiotics as adjuvants in vaccine strategy: is there more room for improvement?.Vaccines (Basel). 2021;9(8):811. doi:10.3390/vaccines9080811National Center for Complementary and Integrative Health.Probiotics: usefulness and safety.Hills R, Pontefract B, Mishcon H, Black C, Sutton S, Theberge C.Gut microbiome: profound implications for diet and disease.Nutrients. 2019;11(7):1613. doi:10.3390/nu11071613Mazziotta C, Tognon M, Martini F, Torreggiani E, Rotondo JC.Probiotics mechanism of action on immune cells and beneficial effects on human health.Cells. 2023;12(1):184. doi:10.3390/cells12010184Bernaola Aponte G, Bada Mancilla CA, Carreazo NY, Rojas Galarza RA.Probiotics for treating persistent diarrhoea in children.Cochrane Database Syst Rev. 2013;2013(8):CD007401. doi:10.1002/14651858.CD007401.pub3Zhang H, Yeh C, Jin Z, et al.Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate.Synth Sys Biotech. 2018;3(2):113-120. doi:10.1016/j.synbio.2018.03.001Harvard Health Publishing.How to get more probiotics.

11 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB.Impacts of gut bacteria on human health and diseases.Int J Mol Sci. 2015;16(4):7493-7519. doi:10.3390/ijms16047493Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ.The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies.Nutrients. 2021;13(3):886. doi:10.3390/nu13030886Khalesi S, Bellissimo N, Vandelanotte C, Williams S, Stanley D, Irwin C.A review of probiotic supplementation in healthy adults: helpful or hype?Eur J Clin Nutr. 2019;73(1):24-37. doi:10.1038/s41430-018-0135-9King S, Glanville J, Sanders ME, Fitzgerald A, Varley D.Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis.Br J Nutr. 2014;112(1):41-54. doi:10.1017/S0007114514000075Peroni DG, Morelli L.Probiotics as adjuvants in vaccine strategy: is there more room for improvement?.Vaccines (Basel). 2021;9(8):811. doi:10.3390/vaccines9080811National Center for Complementary and Integrative Health.Probiotics: usefulness and safety.Hills R, Pontefract B, Mishcon H, Black C, Sutton S, Theberge C.Gut microbiome: profound implications for diet and disease.Nutrients. 2019;11(7):1613. doi:10.3390/nu11071613Mazziotta C, Tognon M, Martini F, Torreggiani E, Rotondo JC.Probiotics mechanism of action on immune cells and beneficial effects on human health.Cells. 2023;12(1):184. doi:10.3390/cells12010184Bernaola Aponte G, Bada Mancilla CA, Carreazo NY, Rojas Galarza RA.Probiotics for treating persistent diarrhoea in children.Cochrane Database Syst Rev. 2013;2013(8):CD007401. doi:10.1002/14651858.CD007401.pub3Zhang H, Yeh C, Jin Z, et al.Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate.Synth Sys Biotech. 2018;3(2):113-120. doi:10.1016/j.synbio.2018.03.001Harvard Health Publishing.How to get more probiotics.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB.Impacts of gut bacteria on human health and diseases.Int J Mol Sci. 2015;16(4):7493-7519. doi:10.3390/ijms16047493Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ.The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies.Nutrients. 2021;13(3):886. doi:10.3390/nu13030886Khalesi S, Bellissimo N, Vandelanotte C, Williams S, Stanley D, Irwin C.A review of probiotic supplementation in healthy adults: helpful or hype?Eur J Clin Nutr. 2019;73(1):24-37. doi:10.1038/s41430-018-0135-9King S, Glanville J, Sanders ME, Fitzgerald A, Varley D.Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis.Br J Nutr. 2014;112(1):41-54. doi:10.1017/S0007114514000075Peroni DG, Morelli L.Probiotics as adjuvants in vaccine strategy: is there more room for improvement?.Vaccines (Basel). 2021;9(8):811. doi:10.3390/vaccines9080811National Center for Complementary and Integrative Health.Probiotics: usefulness and safety.Hills R, Pontefract B, Mishcon H, Black C, Sutton S, Theberge C.Gut microbiome: profound implications for diet and disease.Nutrients. 2019;11(7):1613. doi:10.3390/nu11071613Mazziotta C, Tognon M, Martini F, Torreggiani E, Rotondo JC.Probiotics mechanism of action on immune cells and beneficial effects on human health.Cells. 2023;12(1):184. doi:10.3390/cells12010184Bernaola Aponte G, Bada Mancilla CA, Carreazo NY, Rojas Galarza RA.Probiotics for treating persistent diarrhoea in children.Cochrane Database Syst Rev. 2013;2013(8):CD007401. doi:10.1002/14651858.CD007401.pub3Zhang H, Yeh C, Jin Z, et al.Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate.Synth Sys Biotech. 2018;3(2):113-120. doi:10.1016/j.synbio.2018.03.001Harvard Health Publishing.How to get more probiotics.

Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB.Impacts of gut bacteria on human health and diseases.Int J Mol Sci. 2015;16(4):7493-7519. doi:10.3390/ijms16047493

Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ.The interplay between the gut microbiome and the immune system in the context of infectious diseases throughout life and the role of nutrition in optimizing treatment strategies.Nutrients. 2021;13(3):886. doi:10.3390/nu13030886

Khalesi S, Bellissimo N, Vandelanotte C, Williams S, Stanley D, Irwin C.A review of probiotic supplementation in healthy adults: helpful or hype?Eur J Clin Nutr. 2019;73(1):24-37. doi:10.1038/s41430-018-0135-9

King S, Glanville J, Sanders ME, Fitzgerald A, Varley D.Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis.Br J Nutr. 2014;112(1):41-54. doi:10.1017/S0007114514000075

Peroni DG, Morelli L.Probiotics as adjuvants in vaccine strategy: is there more room for improvement?.Vaccines (Basel). 2021;9(8):811. doi:10.3390/vaccines9080811

National Center for Complementary and Integrative Health.Probiotics: usefulness and safety.

Hills R, Pontefract B, Mishcon H, Black C, Sutton S, Theberge C.Gut microbiome: profound implications for diet and disease.Nutrients. 2019;11(7):1613. doi:10.3390/nu11071613

Mazziotta C, Tognon M, Martini F, Torreggiani E, Rotondo JC.Probiotics mechanism of action on immune cells and beneficial effects on human health.Cells. 2023;12(1):184. doi:10.3390/cells12010184

Bernaola Aponte G, Bada Mancilla CA, Carreazo NY, Rojas Galarza RA.Probiotics for treating persistent diarrhoea in children.Cochrane Database Syst Rev. 2013;2013(8):CD007401. doi:10.1002/14651858.CD007401.pub3

Zhang H, Yeh C, Jin Z, et al.Prospective study of probiotic supplementation results in immune stimulation and improvement of upper respiratory infection rate.Synth Sys Biotech. 2018;3(2):113-120. doi:10.1016/j.synbio.2018.03.001

Harvard Health Publishing.How to get more probiotics.

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