When choosing a probiotic, it’s easy to become overwhelmed. There are so many different types and strains on the market. And though our knowledge of probiotics has grown considerably over the past decade — almost 20,000 scientific reports have been published in the last 10 years — we are still beginning to understand the extent of their usefulness and benefits. 

What Are Probiotics? 

Lactobacillus acidophilus (La-14) 

Probiotic cultures usually have three names. In this example, Lactobacillus is the “genus” and acidophilus is the “species”. Genus is like an extended family (uncles, aunts, and cousins) for the bacteria while the species is the immediate family (parents, siblings). The La-14 represents to unique identity or strain of that bacteria.

Probiotics come in capsules, chewables, powders, and sometimes gummy formulas. They are considered safe for all ages and anyone with a healthy functioning immune system. Those who are immune-compromised should consult with their physician prior to taking a probiotic. I personally prefer formulations where refrigeration is optional, as they are likely more stable.

The minimal dose recommended for children and adults is usually 5 billion CFU (colony-forming units). Teens and adults can take up to 100 billion CFUs once or twice per day. In total, it is estimated that most people have between 40 to 50 trillion bacteria in their bodies, mostly in the gut. This is more than the estimated 30 trillion human cells present. 

Health Benefits of Probiotics

Traditionally, probiotics are considered and used for the following:

  • Help soothe digestive issues 
  • Help relieve infantile colic
  • Irritable bowel syndrome management
  • Crohn’s disease and ulcerative colitis management
  • Prevent urinary tract infections
  • Prevent yeast infections

However, studies are now showing that probiotics may also be helpful for other conditions.

1. Acne Benefits

If there’s one medical issue that afflicts teenagers and young adults more than any other, that condition is acne. Caused by excess sebum—an oily secretion produced by the skin’s sebaceous glands—and dead skin cells that block up hair follicles, acne “breakouts” often appear on the face, but can also pop up on the neck, back, chest, and shoulders. 

Those with acne are suspected to have an altered gut microbiome, which appears to affect the health of the complexion (a prior article has discussed natural approaches to acne). A 2018 study showed those with acne concerns have lower levels of firmicutes bacteria in their gut, but higher levels of bacteroides. Restoring intestinal balance may be an important step for treating acne. 

According to studies, the most significantly depleted gut bacteria in those with acne are a species of bacteria known as clostridia, lachnospiraceae, and ruminococcaceae, which are believed to be beneficial bacteria. Researchers concluded that patients with acne vulgaris had gut microbial dysbiosis, or an imbalance. 

According to a 2018 study, those with acne had lower levels of the following bacteria in their gut: bifidobacterium, butyricicoccus, coprobacillus, lactobacillus, and allobaculum. Consuming a healthy diet along with taking a comprehensive probiotic formula encourages a healthy gut and could help those with acne. 

2. Anxiety Benefits

Anxiety plagues millions of people worldwide. It can present in different forms with varying symptoms and severities. It is not uncommon for patients to visit an emergency room because they are experiencing chest pain, headaches, abdominal pain, or even heart palpitations only to find out that they are suffering symptoms of anxiety. Over my career, I have admitted hundreds of patients who thought they were having a heart attack – ultimately, the tests showed their heart was fine, and anxiety was the culprit. 

Many people turn to prescription medications to help manage chronic anxiety or, possibly, to help get through an acute anxiety attack. While helpful, a prescription medication is not always the answer and should be used with extreme caution — and only under a doctor’s continuous care. 

A 2011 study showed the benefit of bifidobacterium longum in controlling anxiety symptoms. Similarly, a 2016 study in Nutrition Research showed the psychological benefits of probiotics in those with anxiety and depression symptoms. A subsequent 2017 study concluded that that probiotic consumption could have a “positive effect on psychological symptoms of depression, anxiety, and perceived stress in healthy human volunteers.”

However, a 2018 study was less promising. Researchers found that “The evidence for the efficacy of probiotics in alleviating anxiety, as presented in currently published RCTs, is insufficient. More reliable evidence from clinical trials is needed before a case can be made for promoting the use of probiotics for alleviating anxiety.”

For those who suffer from anxiety, a healthy diet, regular exercise, and a probiotic is frequently recommended. 

3. Constipation Benefits

Constipation — having infrequent bowel movements or difficulty passing stool — is a common medical issue, affecting up to 20 percent of the population. Usually defined as having fewer than three bowel movements per week, the condition is considered chronic if it persists for more than two weeks. Frequently, a person suffering from constipation will end up in the emergency room due to severe pain and discomfort. 

Even though constipation is common, it should not be ignored. Its root cause should always be sought, especially if symptoms do not improve after a few weeks of self-treatment. Consulting with your physician is important to ensure no underlying health condition is a contributing factor.

A 2014 study in the American Journal of Clinical Nutrition evaluated adults with constipation. This meta-analysis included 1182 patients and found that probiotics reduced gut-transit time by 12 hours and increased stool frequency by 1.3 bowel movements per week. Specifically, the bifidobacterium lactis strain increased bowel movements by up to 2.5 per week. 

A 2017 study from China showed that probiotics increase stool frequency and have beneficial effects in children. The primary strains used were lactobacillus rhamnosus and lactobacillus casei.

4. Diarrhea Benefits

Diarrhea is common in those with irritable bowel syndrome (IBS) and also is a common side effect seen in those on antibiotics. I have had patients report up to 10 bowel movements in a 24 hours period as a normal thing for them. During these episodes, one is unlikely to absorb the nutrients required to maintain a healthy mind and body. Getting to the root cause of the diarrhea is critical to prevent additional and possibly serious health ailments. 

Antibiotic medication-induced diarrhea is frequently caused by overgrowth of a pathogen called clostridium difficile. If left untreated, it can be life-threatening. Complications occur as healthy bacteria are killed by the antibiotic, allowing overgrowth of the harmful bacteria. 

A 2017 study reported Cochrane Review found probiotics beneficial in treating diarrhea. The researchers looked at 39 studies which, in total, included 9,955 participants and found that probiotic use helped reduce the risk of clostridium difficile-associated diarrhea. The scientists concluded, “The short-term use of probiotics appears to be safe and effective when used along with antibiotics in patients who are not immunocompromised or severely debilitated.” Those who are severely infirmed should consult with their physician prior to taking. 

A 2019 study in the Journal of Digestive Diseases evaluated 10 randomized controlled trials, including 6,634 patients. The researchers found that the lactobacilli strains of probiotics were good at preventing clostridium difficile-associated diarrhea (CDAD) and antibiotic-associated diarrhea (AAD).

Not all causes of diarrhea are bacterial, though, and sometimes they are viral in origin. For instance, rotavirus is a common cause of pediatric viral diarrhea or gastroenteritis. Without treatment, it can result in severe dehydration and death. 

A 2002 study showed that in “...children from day-care centers with mild gastroenteritis, the combination of Lactobacillus rhamnosus and Lactobacillus reuteri was effective in reducing the duration of diarrhea.” In other words, probiotic supplements used by children can help lessen the effects of diarrhea caused by a virus. 

A 2019 study evaluated 80 children with watery diarrhea—half were given a probiotic supplement, while the others were given a placebo. The children, whose average age was 24 months, were monitored for five days. At the end of the study, it was concluded that probiotics were “significantly more effective” at reducing the frequency of diarrhea than the placebo. 

Both children and adults appear to benefit from probiotic supplementation. 

5. Depression Benefits

Depression is a mood disorder associated with sadness and loss of pleasure in life. It can become so severe that it can lead to social withdrawal, substance abuse, and sometimes, even suicide. Worldwide, millions of people are affected by depression—it can occur in anyone, at any age, from any social and economic background. Ensuring one has a healthy diet and lifestyle, which ultimately affects the gut microbiome, is an important part of managing the condition.

A 2016 study in Nutrients found that probiotics were associated with significantly reducing depression symptoms. The strains used included lactobacillus and bifidobacteria. A 2017 population-based, cross-sectional study evaluated patients who consumed probiotic foods or supplements. The results did not show probiotic consumption to be associated with a lower risk of depression. However, this study had serious limitations. 

Lastly, a 2019 study in Nutritional Neuroscience reviewed probiotics and their effects on anxiety and depression. Six of the 12 studies evaluated showed that probiotics could reduce depression symptoms. Two of the 12 studies showed a reduction in anxiety symptoms. There were no negative effects. 

Many with depression take a probiotic, which can safely be taken with antidepressant medications to help with symptoms. 

6. Eczema Benefits

Eczema is a medical condition that affects the skin. Those afflicted will develop patches of red, itchy, cracked skin, usually on their arms or behind the knees. Other areas can also be affected. 

A 2013 study showed that children younger than two years of age who supplemented with lactobacillus and bifidobacteria had a reduced incidence of eczema when compared to those who were not given probiotics. 

A 2019 study evaluated 280 children with no history of eczema. The average age at the beginning of the study was 10 months. The study was a double-blind, placebo-controlled trial — half the children (144) were given a daily mixture of lactobacillus rhamnosus and a bifidobacterium probiotic. The other half (146 children) were given a placebo pill. The study lasted for six months. At the end of the study, 4.2% of those in the probiotic group were diagnosed with eczema, while 11.5% of those who took a placebo had developed eczema. This study showed that probiotics could help prevent eczema from starting! In children this young, probiotic drops are easier to administer.

Likewise, a 2019 study evaluated pregnant women and eczema risk in offspring. In total, 18 randomized controlled trials were evaluated, which included 4,356 pregnant women. The results showed no negative side effects. The women who took the probiotics were 72 percent less likely to have children with eczema symptoms when compared to those women who took the placebo. 

Probiotics are considered safe for both pregnant women and children alike. However, one should always consult with their physician prior if pregnant. 

7. Insomnia Benefits

Insomnia is said to be present when one has trouble falling or staying asleep. Traditionally, many take melatonin to help reset the circadian rhythm. When that does not work, prescription medication is often sought. However, for many, the side effects and addiction risk are problematic. Restoring balance to the gut microbiome may be beneficial to a good night's sleep, likely due to the positive effect on the gut-brain axis. This may also explain why certain teas, which act as prebiotics, may help one rest comfortably. 

A 2019 study in Nutrients showed that lactobacillus fermentum could be helpful with sleep improvement. The study evaluated mice and found that this probiotic strain helped improve sleep by increasing the expression of the gene which makes the adenosine 1 receptor in the hypothalamus of mice. 

In addition, a 2019 study using mice showed that strains of lactobacillus brevis may have beneficial effects on insomnia and circadian rhythm disorders. While we need more studies to help strengthen the evidence, there was no evidence of harm.

8. Weight Management Benefits

Being overweight (BMI 25-30) and obesity (BMI >30) are emerging health threats that increase the risk for cancer, diabetes, heart disease, stroke, sleep issues, and more. It is estimated that up to one in three people worldwide will be clinically obese over the next 20 years if the current trend continues. 

Diet and exercise habits play a major role in both the prevention and development of obesity. However, scientists are now realizing that one reason obesity may be becoming more prevalent is that the human gut microbiome is being altered by our food supply, additives, and chemicals. A shift in a person’s gut bacterial diversity appears to be a contributing factor to weight gain. 

Obesity and gut microbiome studies have shown that those who are overweight or obese and have insulin resistance have a different variety of gut bacteria when compared to those who are thinner and not at risk for diabetes. 

The gut appears to function like a unique metabolic organ, burning a certain amount of calories (kilocalories) depending on the diversity of the bacteria.

A 2014 study showed the bacteria lactobacillus rhamnosus, in addition to bifidobacterium, may reduce adiposity and body weight, and prevent weight gain. These are common strains found in most probiotic supplements. Likewise, a 2019 study showed lactobacillus rhamnosus has an anti-obesity effect in mice caused by regulating the gut bacteria and reducing inflammation. More studies are currently underway to help us clearly determine a useful treatment plan using probiotics.

9. Urinary Health Benefits

Urinary tract infections, or UTIs as they are commonly called, are more prevalent in women than men. In the United States alone, more than 500,000 people are admitted to the hospital each year due to complications of urinary tract infections. 

The most common complication of a urine infection is a bacterial infection of the blood. It is estimated that one in 10 women have had a urinary infection in the prior 12 months. In addition, it is estimated that one in two women will develop at least one urinary tract infection during her lifetime. 

Some studies show that those who take routine probiotics orally can reduce their risk for recurrent urinary tract infections. A 2011 study of women using vaginal probiotic supplements showed benefit in the prevention of urinary tract infections. A 2013 study suggested that oral lactobacillus may prevent urinary tract infections. Other studies, however, have not supported these findings. 

There was no evidence of harm. At a minimum, probiotics should be considered if one is taking antibiotics for a bladder infection as this may prevent a bad case of diarrhea. Further, a 2017 study showed that the probiotic yeast strain Saccharomyces boulardii could help prevent vaginal yeast infections in those who complete a course of antibiotics.


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