Are There Probiotics That Actually Work? Here’s What to Know

Probiotics are growing in popularity and at a rapid rate, with the probiotic market expected to reach a whopping 105.7 billion USD by the year 2029. The wellness market is booming: people are prioritizing their lifestyle, diet, and health more than ever before, utilizing probiotics as a cost-effective adjunct to potential longevity. But do probiotics actually work? This article will consider the effectiveness of probiotics, considering the scientific research behind the products.

What are probiotics?

The term 'probiotic' was coined by German bacteriologist Werner Kollath in 1953, from the Latin word 'pro' and the Greek word 'βιο' meaning ‘for life.' Probiotics contain live microorganisms, or yeast, which have a range of beneficial properties (also referred to as ‘good bacteria’). Probiotics can be found in several food sources, such as fermented foods and yogurt. Still, the increase in scientific evidence surrounding their numerous health benefits has resulted in a wide range of probiotic supplements, which can often be bought over the counter.

Probiotic supplements add to your existing supply of ‘good’ microbes, helping fight off harmful pathogenic bacteria whilst also boosting your immunity against infections, maintaining the balance of gut microflora, and strengthening the gut barrier. The gut microbiome refers to the microorganisms residing in the digestive tract alongside viruses, protozoa, fungi, and their collective genetic material. The body of evidence suggesting that the gut microbiome plays a crucial role in many aspects of health and disease is vast (and growing), having already established its involvement in human metabolism, nutrition, physiology, and immune function. Probiotics interact with the gut microbiome in a number of different ways.

The beneficial mechanisms of probiotics are achieved through enhancing intestinal homeostasis, intestinal barrier function, host immunity, and gut microbiome. Many probiotics are used as an adjunct to physical health, however, mental health probiotics have also been considered to be potentially beneficial in depression, having a valid basis rooted in the microbiota-gut-brain axis mechanisms.

Probiotic guide: are there probiotics that actually work?

Scientific evidence allows us to determine which strains of probiotics actually work and for what? By gathering evidence from clinical trials, we can determine the strains of probiotics to be utilized for our health concerns, considering which specific probiotic benefits we may need.

The Lactobacillus casei group (LCG), composed of the closely related Lactobacillus casei, Lactobacillus paracasei, and Lactobacillus rhamnosus, are some of the most widely researched and applied probiotic species, with reported health benefits including cholesterol-lowering effects, ability to prevent diarrhea, gastrointestinal disorders, and relapses in subjects with chronic inflammatory bowel disease. Considering specific strains within the Lactobacillus genus can determine on a much more precise level how these probiotic strains may impact and enhance your health.

Lactobacillus acidophilus

Lactobacillus acidophilus is one of the most commonly used microorganisms, as it is thought to have various beneficial effects on human health. The main biological effects of related strains of Lactobacillus acidophilus include potentially improving gastrointestinal diseases and inflammatory disorders, reducing risks of cardiovascular disease progression, improving lactose intolerance, and regulating immune capacity. For immune support probiotics, you may want to consider a probiotic that includes Lactobacillus acidophilus.

Lactobacillus rhamnosus

Lactobacillus rhamnosus GG (LGG) is another one of the most widely used probiotic strains. Various health effects include improvements in gastrointestinal infections and diarrhea and the stimulation of immune responses that promote vaccination or even prevent certain allergic symptoms.

Lactobacillus casei

Lactobacillus casei has shown some antihypertensive and anti-hyperglycemic effects, antioxidant properties, and improved lipid profile. In one double-blind, placebo-controlled trial, the probiotic strain Lactobacillus casei was administered to healthy medical students exposed to academic stress for eight weeks, significantly reducing gastrointestinal symptoms. Another double-blind, placebo-controlled, parallel-group trial found that intake of Lactobacillus casei is effective for improving skin conditions, making this particular strain a potential addition to skin health probiotics.

Lactobacillus plantarum

Lactobacillus plantarum is a bacteria widely considered for its applications in immune system regulation, reduction of cholesterol levels, and keeping intestinal flora in balance. Other applications include a reduction in symptoms such as abdominal pain and bloating in irritable bowel syndrome (IBS). Because of this evidence, you may find that probiotics for IBS include the strain Lactobacillus plantarum.

Types of probiotic supplements

Probiotics can be taken in a variety of ways to suit your individual needs or preferences. If you are struggling to add probiotic foods into your diet or have specific health needs that require a targeted probiotic strain, you may opt for a probiotic supplement. Supplements come in several different forms, including:

• Capsules
• Tablets
• Powders
• Gummies
• Liquid supplements

Your choice may depend on individual preferences, such as ease of swallowing, taste, or convenience, but it is also important to consider the potency and stability of products. For example, capsules often remain stable and potent until they reach the gut, whilst gummies may have lower probiotic counts and reduced stability due to the added sugar and moisture content.

Researching the benefits of different types of products can help you to pick the best product for your needs. It is always advised to discuss any new supplement regimen with a healthcare provider before implementation, who can advise on the best strain and product type to use in relation to your individual health needs.

How do you make probiotics work best?

The benefits of probiotic supplementation can be enhanced by ensuring you take them effectively. How? Not only is it vital to choose the correct strain of probiotic for your individual health needs, but taking supplements consistently and at appropriate times during the day can enhance the overall benefits. Taking probiotics with meals (or just prior) can improve their survival through the digestive tract, whilst taking probiotics at the same time every day can ensure levels remain consistent within the digestive tract.

Prebiotics help probiotics to thrive within the gut. The probiotics use the prebiotics as a food source, enabling them to survive for a longer period of time inside the human digestive system than would otherwise be possible. There are ongoing debates surrounding the benefits of probiotics vs. prebiotics, however, some probiotic products also contain prebiotics, which are called synbiotics. Check the label to determine whether or not prebiotics are included in the product, or add prebiotic foods into your diet, such as garlic, onions, bananas, or asparagus, to improve efficacy.

Probiotic foods to incorporate into your diet

Natural probiotics can be found in a wide range of different food products, which can easily be incorporated into your diet.

Yogurt is one of the best sources of probiotics. Yogurt naturally contains probiotics as a result of the fermentation process, mainly Lactobacillus bulgaricus and Streptococcus thermophilus. However, probiotics can also be added to yogurt by manufacturers to enhance the proposed health benefits of the product. Choose yogurt with live and active cultures, and always check the label to see which strains of probiotics are included.

A number of fermented foods also contain probiotics. Kefir is a fermented probiotic milk drink that contains several major strains of friendly bacteria and yeast, such as Lactobacillus kefiri and Saccharomyces kefir. According to scientific research, consuming kefir regularly has been associated with improved digestion and tolerance to lactose, lower cholesterol, effective glucose control, reduced blood pressure, anti-inflammatory effects, antioxidant activity, and anti-allergenic activity, whilst also being considered as a potential to reduce risks of cancers, also known as anti-carcinogenic.

Other probiotic foods include cottage cheese, fermented cabbage or soybeans, kombucha (fermented tea), pickles, and buttermilk. When considering food products based on their inclusion of probiotics, it is always advised to check the labels for inclusion of probiotic strains that have been clinically proven to help improve health. Probiotics for kids are often best found in the form of natural food sources.

How to choose the probiotic that works

Choosing probiotics that work is dependent on a range of different factors. One of the most important factors to consider is the appropriate strain for your health needs. Many probiotic products lack confirmatory trials, and not all probiotic products are equally effective for all conditions or individuals, which is why ensuring the most beneficial strain for your health needs is so important.

Always look for a product that has been tested and has been proven to work specifically for your individual health needs, backed by scientific research.

Probiotics are measured in colony-forming units (CFUs), indicating the number of viable cells. A higher level of CFUs is often promoted as an indication of product quality and effectiveness, with the average CFU count typically within the range of 1 and 10 billion CFUs per serving. However, this may be one of many probiotic myths. CFUs are just one consideration when choosing the best product for your needs. For the best probiotics, your choice should reflect findings from clinical research studies, as indicated for your individual health needs.

Look for products labeled with the number of CFU at the end of the product’s shelf life, not at the time of manufacture, as these can die during shelf life. The World Gastroenterology Organisation (WGO) notes that the optimal dose of probiotics depends on the strain, product, and indication of use. We would always advise consulting with a healthcare professional to determine the most appropriate strain of probiotic and dosage for your individual health needs.

Quality indicators should always be considered. Given the lack of regulation around the provision of probiotics, it would be wise to consider a product that has undergone appropriate and transparent third-party testing. This can help ensure products have undergone independent testing in relation to product potency, viability, risk of contaminants, and verification of ingredients, ensuring the overall quality of the product.

Always check the manufacturer’s guide for storage, as some products may need to be refrigerated to stay effective.

Conclusion

Probiotics can be used as an effective adjunct for many different health concerns if the correct strain is taken. Research into their effects and impact on many conditions, diseases, and health concerns is ongoing, with randomized controlled trials remaining the gold standard for scientific testing. The most effective probiotics have been appropriately tested and have been proven to enhance health, as backed by scientific research.

Consider probiotics as additional to a healthy lifestyle, including a healthy diet, exercise, and overall well-being measures. Probiotics are not intended to be taken in place of appropriately prescribed medications, and any new supplement regimen should always be considered alongside advice and assessment from your healthcare provider, as some contraindications exist. It is important to consider probiotic side effects.

Article history

Our experts strive to provide up to date information and update articles when new information becomes available

July 15, 2024

Co-written by Urtė Gumuliauskaitė, MSci

July 12, 2024

Fact checked by Alifia Fernandes Jokubauskienė, MPharm

July 12, 2024

Written by Bethany Cooper, BSc, MSc, RN, PhD Candidate