What are probiotics?
Probiotics are live bacteria and yeasts that live naturally within the gastrointestinal tract and provide numerous health benefits. Probiotics play important roles in the healthy functioning of the mind and body, particularly in protecting the gut and immune system.
What's the benefit of probiotics?
Here’s a quick overview of the many health benefits of probiotics and how they can assist with various functions in the body.
Supporting immune function
The gastrointestinal tract contains billions of bacteria that are intrinsically linked to the maturation of immune cells. In the gut itself, bacteria coexist with one other and with the immune cells within the intestinal villi. This intestinal microbiota stimulates the maturation and functionality of the immune cells through their metabolites. Probiotic bacteria have significant effects on the functionality of the mucosal and systemic immune systems through the activation of multiple immune mechanisms.
As well as enhancing the immune response, probiotics fight invading pathogens by directly killing them, and “crowding” them out (competing with them for nutrients). 
Preventing and treating digestive disorders
Probiotics restore normal bacterial microflora and improve the functioning of the gastrointestinal tract in a number of ways, including down-regulating inflammation, reducing harmful and gas-producing bacterial species, improving bacterial flora, enhancing epithelial barrier function, and more. These mechanisms have been shown to benefit disorders such as antibiotic-associated diarrhea, Clostridium difficile colitis, infectious diarrhea, ulcerative colitis, Crohn’s disease, pouchitis, and irritable bowel syndrome. 
Optimizing gut function
One of the best-known benefits of a probiotic is in assisting with healthy gut function. Probiotics help to reduce or prevent gut inflammation and other intestinal disorders by rebalancing healthy bacteria in the gut and introducing more beneficial microbial communities. They also help to suppress pathogens, support immune cells, stimulate epithelial cell proliferation and differentiation, as well as strengthening the intestinal barrier. 
Supporting cardiovascular health
Accumulating evidence shows probiotics can lower LDL (harmful) cholesterol and improve the LDL/HDL ratio, as well as lowering blood pressure, reducing inflammatory mediators, balancing blood glucose levels and improving body mass index. These cardiovascular benefits make probiotics an important part of any health regime, but even more so for those affected by heart disease or high cholesterol. 
Reducing gas and bloating
Specific probiotics may help reduce bloating/distension and improve bowel movement frequency and consistency. Some studies have reported that probiotics have a significant beneficial effect (vs placebo) in reducing gas, bloating and abdominal distension in patients with IBS (Irritable bowel syndrome). 
Helping to protect against colds and flu
Taking probiotics has been shown to significantly reduce the incidences of URTI (upper respiratory tract infection) and flu-like symptoms compared to placebo. A 2021 study found that supplementation with Lactobacillus plantarum and Lactobacillus paracasei helped to protect against multiple colds in adults who were prone to colds. 
Reducing the severity of allergies and eczema
Oral probiotics, especially strains of bacteria of the genus Lactobacillus, are effective in reducing the severity of atopic dermatitis.  Probiotics improve the general microbiome and immune function by strengthening the intestinal barrier, which helps to reduce allergic response and atopic dermatitis severity.
Health benefits of probiotics at different life stages
Benefits of probiotics for women
Probiotics play a vital role in supporting women’s health throughout life. Estrogen levels fluctuate significantly between puberty to menopause and postmenopause, as well as across menstrual cycle and pregnancy. These fluctuations can affect the microbiota composition of the vagina, causing imbalance and/or infection. Probiotics support microbial balance during these stages of life, as well as during antimicrobial treatment or dysbiosis. 
Benefits for men
Some of the many benefits of probiotics for men include supporting prostate health. Probiotics are shown to help reduce inflammation and bacteria associated with prostatitis, including E. coli and E. faecalis. 
Probiotics may also support testosterone by reducing cortisol levels.  High levels of cortisol have been shown to suppress testosterone, which may affect fertility. 
Benefits for children
Probiotics are shown to be beneficial in reducing the severity and incidence of gastroenteritis, diarrhea, and colic in babies. Probiotics may also benefit children's health by supporting the developing immune system. Although children should receive the bulk of their nutrition from their diet, probiotics supplementation can restore low levels of beneficial bacteria and microorganisms in the gut, helping to prevent pathogenic bacteria.  Studies have also shown that probiotics can support normal brain development, decrease the severity of autism symptoms and improve gastrointestinal symptoms in children. 
Benefits for older adults
Bacterial colonies decline with age, with Bifidobacteria shown to decrease by as much as 1,000-fold from the age of 55.  This imbalance can increase susceptibility to gastrointestinal infections and digestive issues. Both probiotics and prebiotics may be helpful in cases of malnutrition, particularly in assisting calcium absorption and improving symptoms of lactose intolerance. They may also help prevent constipation and support immune function in the elderly. 
How often should you take probiotics?
Probiotic supplements vary significantly in terms of their bacterial contents and potency, so there are no specific dosage rules. Most supplements recommend taking 1-2 doses per day (morning and/or night). Follow the directions on the product or consult with a health professional when starting a probiotic regime.
Possible side effects
Initially, a course of probiotics may cause minor gastrointestinal symptoms, such as abdominal cramping, gas, nausea, and soft stools.  However, these symptoms usually pass after the first few days. Probiotics are generally considered safe at any age, but those with autoimmune disorders or chronic gastrointestinal illnesses are advised to speak with their health professional first.
Combining prebiotics with probiotics
Prebiotics such as oligosaccharides are the “food” for probiotic microorganisms. Prebiotics can enhance the benefits of probiotics. Studies have suggested that combining certain prebiotics with probiotic strains may improve their colonization in the gut as well as assist with their antibacterial functions. 
Benefits of probiotic yogurt
Fermented foods such as yogurt are a great source of natural probiotics. Depending on the fermentation process, yogurt may contain beneficial bacterial species such as Bifidobacteria and Lactobacillus, which have a range of benefits for gut health, immune function, and digestion. A systematic review found that yogurt assists with lactose digestion and tolerance, as well as reducing the risk of breast and colorectal cancer, type 2 diabetes. Regular yogurt consumption also improved weight maintenance, and cardiovascular, bone, and gastrointestinal health. 
Choosing the right probiotic supplement
Probiotic supplements are available almost everywhere now, but beware - the quality and effectiveness of different supplements will vary enormously.
To choose an effective probiotic supplement, look first at the quantity of colony-forming units (CFU). A probiotic can have five to 100 billion CFU: the more, the better.
Multiple strains of bacteria are also beneficial. Lactobacillus and Bifidobacterium are among the most researched strains, but yeasts such as Saccharomyces boulardii are also helpful.
A probiotic should also be free from allergens such as dairy and flavourings, as well as fillers and binders.
The best probiotic supplement (and one that ticks all the boxes) is Mega SporeBiotic™, available from Methyl-Life.com. This spore-based, broad-spectrum probiotic contains a blend of 5 Bacillus spores that have been clinically proven to maintain healthy gut barrier function and support the immune system. The Bacillus spores are able to survive the harsh environment of the gut until they reach the large intestine, where they can begin colonizing. Research has shown that Bacillus spores remain viable during their transit through the stomach and germinate successfully in the small intestine within just three hours of ingestion.  However, many mainstream probiotic supplements have poor tolerance to acids and bile salts, which means they may be inactive upon reaching the intestine. 
Mega SporeBiotic™ is dairy-free, soy-free, gluten-free, and non-GMO.
RestorFlora™ is also excellent for improving gut health, especially for those who have taken antibiotics and/or have suffered gastrointestinal illness. It contains a dual-action blend of beneficial yeast Saccharomyces boulardii and two strains of probiotic Bacillus species, all of which are shown to assist with digestive function and help maintain a healthy intestinal environment. RestorFlora™ supports regular bowel movements, normal detoxification, and immune function.
The health of our gastrointestinal tract depends on a complex ecosystem of bacteria and yeasts. These microorganisms have numerous roles in the body, particularly in supporting the immune system and assisting with digestion. Taking probiotic supplements can help to restore and maintain these colonies of bacteria, which can then contribute to better overall health.
Probiotics can provide benefits for every life stage, from supporting normal development in children to assisting with hormone-related fluctuations in adults. Supplementation is especially important if gut bacteria have been depleted by infection or antibiotic treatment.
Clinically researched probiotic supplements such as Mega SporeBiotic™ or RestorFlora™ have been shown to help restore normal flora in the gut, strengthening digestive function and immunological response.