Medically Reviewed by: Chris Duncombe, M.D.
In a time when society is burdened by high-stress work environments, low-quality fast food, fatigue, and an obsession with antibiotics, natural gut flora is under attack. Our digestive systems are deprived of their natural, health-promoting microorganisms, and bacteria that causes illness takes over.
Probiotics, which have received significant attention over the past few decades, have been touted as being the solution to all your gut woes.
In this article, we review the basics of probiotics, and summarize what the research says about how probiotics can help treat multiple digestive illnesses.
What are Probiotics?
Our gut is naturally a perfect breeding ground for bacteria. When we think of bacteria, our minds might lead us to think of infection, inflammation, and illness – nothing good.
This is, indeed, true for many types of bacteria, especially when they aren’t where they are supposed to be.
For example, when you get a cut or a scrape, and bacteria found naturally in the environment find their way in and start multiplying, infection can occur. The same happens in the gut; when pathogenic, or “bad” bacteria make their way into the gut, you can get stomach infections which can cause uncomfortable symptoms.
However, when certain types of bacteria are where they are supposed to be, they actually form part of the barriers that prevent bodily infection. This is the case for probiotics.
Probiotics are live bacteria and yeast that survive our digestive system and colonize the gut. Unlike pathogenic bacteria, they are “good” for our gut and have the capacity to displace bacteria that make us sick.
Probiotics are found naturally in our gut already, but sometimes illness, medications (especially antibiotics), or an imbalanced immune system can reduce the population of these health-promoting microorganisms.
“Good” bacteria have a series of responsibilities in the digestive process, so a low population of probiotics can cause digestive problems. To make matters worse, if exposed, illness-causing bacteria can take their place and bring a slew of problems along with it.
Are probiotics effective in helping with digestive problems?
In this section, we will briefly describe the role that probiotics have in helping to relieve the following illnesses:
• Constipation
• Diarrhea
• Severity of Lactose Intolerance
• Gas and Bloating
• Inflammation
Constipation
Health specialists have long known that probiotics are effective at regulating bowel movements, including irregular or infrequent evacuations.
One of the most recent systematic reviews focuses specifically on the effect of probiotics on constipation in adults concluded that “probiotics may improve whole gut transit time, stool frequency, and stool consistency”. In this study it was found that B. lactis seemed to have a particularly positive effect on constipation.
Diarrhea
Early on, researchers found that consuming foods with significant probiotic populations help to improve diarrhea.
Since the agents that cause diarrhea often destroy cells that are necessary for healthy colonic movement, it makes sense that killing or displacing the “bad” bacteria with beneficial bacteria could improve the state of the colon and the frequency with which it needs to evacuate.
Studies show that probiotics help to treat diarrhea caused by antibiotics as well as by infection, making it an effective treatment for all ages at the correct dose.
Severity of Lactose Intolerance
One of the by-products of some strains of good bacteria in the gut is lactase.
Some probiotic strains cultivated in fermented milk products result in delayed gastrointestinal transit, positive effects on intestinal function, and reduced sensitivity to symptoms. However, it seems that lactose intolerance treatment with probiotics is much more effective with certain strains like Lactobacillus sp. and Bifidobacterium sp.
Gas, Bloating and IBS
A systematic review of studies concluded that probiotics can help alleviate the discomfort associated with IBS (irritable bowel syndrome), flatulence, and abdominal pain. Of the 43 studies reviewed, it was found that, in most cases, probiotics helped to alleviate uncomfortable symptoms of IBS, reduced gas and flatulence, and alleviated the feeling of bloating. What isn’t clear as of yet is what makes certain strains more effective than others.
How do Probiotics Work?
According to the American Nutrition Association, probiotics work by:
• Crowding out potential pathogens and replace them with beneficial bacteria
• Producing anti-microbial and anti-viral substances to kill off bad bacteria and viruses
• Producing vitamin K, folic acid and biotin
• Supporting protein digestion
• Breaking down toxins that result from natural metabolism
• Normalizing the time it takes for feces to travel through the bowel
• Helping reduce the pH of the colon by producing lactic acid
These functions help to treat constipation and diarrhea, and alleviate bloating and inflammation, among others.
Where can you find probiotics?
Probiotics are naturally found in several foods, including soy products (like soy drinks and tempeh), fermented milk, yogurt, buttermilk, soft cheeses, and fermented foods like miso, tempeh, kim chi, kombucha, sauerkraut, and pickles.
When you eat these foods regularly, it will promote a healthy probiotic population in your gut.
If you feel like your digestion needs an extra boost, or if you aren’t a big fan of fermented foods, you can consider taking a dietary probiotic supplement. Probiotic supplements are available as capsules, tablets, and liquid extracts.
Some of the most common types of probiotics are acidophilus, bifidobacteria and lactobacillus, so you can look for these on the bottle.
Keep in mind that not all probiotics are made the same. The bacteria used must be resistant to the acidic environment in your stomach, and it must be a type that can swiftly colonize the gut before the remnants are evacuated during your next bowel movement.
More research is being done about how pharmaceutical companies can make probiotic supplements that work effectively, so make sure to ask your doctor or dietician about which ones will work best for you.
Conclusions
In short, probiotics have a number of positive effects on gut health. They can help treat constipation and diarrhea by recolonizing the gut with good bacteria after having taken antibiotics, but displacing pathogenic bacteria, or by producing a byproduct that is beneficial for our gut environment.
Talk to your dietician about ways to increase your consumption of probiotic-containing foods, or about taking a supplement that can benefit your gut health.