Is There Evidence That Probiotics Are Good for General Health?

The the benefits of probiotics for general health

Check out this answer from Consensus:

Probiotics offer a range of health benefits, including improved gut health, enhanced immune responses, better mental health, and potential cardiovascular benefits. While more research is needed to fully understand their mechanisms and optimize their use, the current evidence supports the inclusion of probiotics as part of a healthy diet for promoting general health.

Probiotics, defined as live microorganisms that confer health benefits to the host when administered in adequate amounts, have garnered significant attention in recent years. This article explores the evidence supporting the positive impact of probiotics on general health, drawing from various research studies.

Gut Health

Probiotics are well-known for their beneficial effects on gut health. They can improve the concentration of beneficial bacteria in the gut microbiota, which is crucial for maintaining a healthy digestive system. Studies have shown that probiotics can enhance stool consistency, bowel movements, and reduce gastrointestinal discomfort in healthy adults1. Additionally, probiotics have been found to alleviate symptoms of lactose intolerance by improving intestinal health6.

Immune System

Probiotics play a significant role in modulating the immune system. They can enhance immune responses, providing protection against various infections and diseases. Research indicates that probiotics can downregulate inflammatory cytokines and induce regulatory mechanisms, thereby offering protection from conditions like colitis and allergic reactions7. Furthermore, probiotics have been shown to improve immune responses in healthy adults, making them a valuable addition to a balanced diet1.

Mental Health

Emerging evidence suggests that probiotics can positively impact mental health through the gut-brain axis. A study on healthy older adults demonstrated that probiotic supplementation improved cognitive function and mood, reduced stress, and increased serum levels of brain-derived neurotrophic factor (BDNF)2. These findings highlight the potential of probiotics to promote mental well-being alongside physical health.

Cardiovascular Health

Probiotics have also been investigated for their cardiovascular benefits. They have been shown to lower low-density lipoprotein (LDL) cholesterol levels, improve the LDL/high-density lipoprotein (HDL) ratio, and reduce blood pressure and inflammatory mediators8. Although the evidence is still evolving, these findings suggest that probiotics could be beneficial in managing cardiovascular risk factors.

Female Reproductive Health

Probiotics can positively influence female reproductive health by increasing vaginal lactobacilli concentration, which helps maintain a healthy vaginal microbiota. This can prevent infections and promote overall reproductive health1.

Limitations and Future Research

While the benefits of probiotics are well-documented, there are limitations to the current research. For instance, the ability of probiotics to cause persistent changes in gut microbiota and improve lipid profiles in healthy adults remains inconclusive1. Additionally, the exact strains and dosages required for specific health benefits need further investigation8. Future research should focus on understanding the mechanisms by which probiotics exert their effects and identifying the most effective strains and dosages for various health outcomes.

 

 

Is there evidence that probiotics are good for general health?

Emma Allen-Vercoe has answered Unlikely

An expert from University of Guelph in Microbiology, Microbiome

Not really, but this is partly because there are so many probiotics available and so few of them have actually been tested for their role in health promotion.  It’s also quite difficult to study health as there is no universal definition for it. Instead, we tend to study disease, where there is quite clearly something wrong, and therefore it’s easy to see if a given intervention can improve the situation. 

Some probiotic strains and formulations have shown modest benefits in the treatment of particular diseases, but these cannot be extrapolated to other strains of the same species.  In other words, a generic probiotic with a similar-sounding name to one which has been proven in trials to have clinical benefits is unlikely to have the same effects.  

There is also a misconception by the public of what actually constitutes a probiotic.  Probiotics have a strict definition (“live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”).  This definition does not include microbes consumed as a component of, for example,  fermented foods, yet many manufacturers of these foods incorrectly and misleadingly identify the live microbes found in those foods as ‘probiotics’, confusing the issue further; often the regulatory bodies that govern food labels also tend to let this incorrect terminology fly, which is unhelpful.  Therefore, the question becomes a difficult one to answer, because the consumer may be unaware of what a probiotic really is.

Fermented foods almost certainly contribute to health as part of a balanced diet, but not necessarily because they contain live microbes. 

 

Is there evidence that probiotics are good for general health?

Kate Secombe has answered Unlikely

An expert from University of Adelaide in Microbiome, Cancer

Most scientific evidence is in the use of probiotics in people with other health conditions, not necessarily in people otherwise in good health.

One systematic review has shown the probiotic use does not significantly change faecal microbiota composition (https://genomemedicine.biomedcentral.com/articles/10.1186/s13073-016-0300-5).

A recent review paper looked at evidence for use of probiotics in healthy adults (https://www.nature.com/articles/s41430-018-0135-9). They reviewed 45 studies and found a few benefits, including reducing abdominal discomfort stemming from constipation, increasing the amount of ‘good’ bacteria in the gut and the vagina, and also a potential role for boosting the immune system. However, these results stopped soon after ceasing probiotic use, so you would need to continuously take probiotics to continue seeing these effects. The authors concluded that eating a healthy and varied diet may be more beneficial. Additionally, more research is required to more fully understand whether having more ‘good’ bacteria in the gut leads to any better health outcomes.

 

Is there evidence that probiotics are good for general health?

Hannah Wardill has answered Unlikely

An expert from University of Adelaide in Gastroenterology, Microbiome

This is a very challenging question, as probiotics have largely been evaluated in disease-specific contexts. Evidence certainly exists demonstrating that probiotics increase the number and diversity of good bacteria residing within our guts (as outlined by other answers), and this has then been extrapolated to suggest that probiotics contribute to good GI function, immune benefits, improved cardiac function and improved blood sugar control. However, these remain fairly correlative, based on the existence of associative data gathered from disease-specific research. As such, the claim that probiotics are good for overall health in a generally healthy individual remains challenging to support. 

Recently, a large scale analysiswas performed to evaluate the level of evidence for or against probiotics in healthy individuals. The study integrated data from over 45 individual studies demonstrated that probiotic supplementation in healthy people can have a few mild benefits. For example, results showed increased diversity and numbers of good bacteria in the gut (again, this is confounded by the techniques used to assess microbial load which cannot differentiate between live/dead bacteria), more regular bowel function (however, this seemed to be reported in people who already had abnormal bowel function – but not a specific diagnosis) and a higher number of good bacteria in the vagina (associated with reduced incidence of vaginosis, yeast infection and UTIs). There was also evidence to suggest “immune boosting” benefits, reducing the duration of the common cold – this evidence is somewhat conflicting though, with only 3 studies supporting this claim. Whilst not reported in this study, there is some emerging evidence probiotics are beneficial in promoting optimal mood/cognitive function, but again this has largely been investigated in people with cognitive impairment of mood disorders.  

It is also critical to interpret these “health benefits”. For example the study found some evidence to support that probiotics reduce cholesterol in healthy individuals, as well as improving blood sugar levels. Whilst this sounds great for our risk of heart disease and diabetes, there is no evidence to that taking probiotics will reduce the risk of heart disease and diabetes. 

Most importantly however, this study also revealed that these benefits were transient, only existing when probiotic use was maintained. As such, probiotics are an expensive and potentially limited method of boosting overall health … with the same, if not more beneficial results seem when the entire microbiome is supported and nourished through a diet rich in fruit and vegetables (both of which contain dietary fibre). 

 

Is there evidence that probiotics are good for general health?

Bruno Pot has answered Likely

An expert from Vrije Universiteit Brussel in Microbiology

A number of health economy studies have indicated that if a total population would consume probiotics, the costs for health care would be considerably reduced. The most recent study (august 2019): https://www.frontiersin.org/articles/10.3389/fphar.2019.00980/abstract

Earlier studies of a similar kind:

https://www.ncbi.nlm.nih.gov/pubmed/25859849

https://www.ncbi.nlm.nih.gov/pubmed/27832195

https://www.ncbi.nlm.nih.gov/pubmed/30219897

https://www.ncbi.nlm.nih.gov/pubmed/27558903

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3926519/

https://link.springer.com/article/10.1186/s40795-016-0115-1

https://www.sciencedirect.com/science/article/pii/S2213434418300707

See also article by the Worls Economic Forum: https://www.weforum.org/agenda/2018/09/probiotics-a-first-look-at-what-s-going-on-in-the-gut/

 

Is there evidence that probiotics are good for general health?

Arthur C Ouwehand has answered Likely

An expert from DuPont Nutrition and Health in Microbiology

The question here is, what is ‘good for general health’? If your health is good, it is unlikely probiotics will make it better. Having said that, if we interpret the question as can probiotics support general health; i.e. to cope with certain health related challenges, the answer (as given above) is probably yes. There is evidence that probiotics may reduce risk for upper respiratory tract infections, they may also reduce risk for community acquired diarrhoea; especially in children. A modest but significant and clinically relevant reduction in disease risk is possible.

https://www.ncbi.nlm.nih.gov/pubmed/30189723

https://www.ncbi.nlm.nih.gov/pubmed/24780623

https://www.ncbi.nlm.nih.gov/pubmed/21901706

 

Is there evidence that probiotics are good for general health?

Paolo Gionchetti has answered Uncertain

An expert from University of Bologna in Gastroenterology

There is some evidence that probiotics are of some help for general health but no evidence yet in controlled studies.

 

Is there evidence that probiotics are good for general health?

Tom MacDonald has answered Uncertain

An expert from Queen Mary University of London in Immunology, Gastroenterology

I am a bit more positive about this. There is a rationale that taking probiotics may protect against infections of the small bowel where there are not so many commensals and they can prevent infection by colonisation resistance. I do not think they have an effect in the colon, they do not colonise and are outnumbered by commensals. Danone did a study in old folk years ago showing that those taking actimel compared to placebo had higher antibody levels following winter flu vaccination. They tried to repeat it but the trial was all messed up.