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     It seems like every week or so someone is promoting a new “superfood” that we simply must be eating in order to be healthy.  Lately, it seems like everywhere I look someone is saying; “Eat probiotics, they’re a superfood!”

     If I ask what makes them so super, the response is often something like, “Well you need good bacteria in your intestines to get rid of the bad bacteria in there.”  In fact, just the other day at the gym I heard a physical therapist telling his client that if she took probiotics she would never again have gas.  When I politely interrupted to ask how this could be possible, he explained that; “You need more good bacteria to fight the bad bacteria.”  When I asked for an example of a bad bacteria, he had none to offer, but did insist that bad bacteria cause gas.

To be honest, he is not wrong about probiotics being “good” bacteria, or that we need more of them than “bad” bacteria.  He is wrong however, on the account that “good bacteria” will alleviate gas.  If anything, probiotic supplementation is associated with more gas.  Bacteria in our intestines eat the food that we eat, they break down a lot of the fibrous foods and one of the end products of their metabolism is gas.  What really irks me that no one ever explains what “bad” bacteria are.  Where does it come from, what does it do that makes it bad?  Before googling the terms good and bad bacteria or probiotics, I decided to search through research papers for some answers.

What makes “good” bacteria good?

In short, our intestinal bacteria weigh up to 2.2 pounds and the bacterial cells outnumber our own human cells by ten to one.  That’s right, we each harbor more bacteria cells than we have cells in our whole body.  On top of that, they help us out by producing nutritional factors such as several B vitamins, vitamin K, folate, and short-chain fatty acids (like the ones found in another super food, coconut oil).  Up to 10% of our daily energy needs can come from the by-products of bacterial fermentation (their digestion).  Gastrointestinal bacteria are also critical for the normal development of our immune system, they stimulate the growth of the intestinal lining and prevent proliferation of disease causing bacteria within the intstine.  The physiological impact these bacteria have on our bodies is significant enough that some in the gastroenterology world call them our “other organ”.

What makes “bad” bacteria bad?

In general, they make us sick, and cause intestinal related illnesses such as diarrhea.  In an interview with food and bioproduct scientist Dr. Darren Korber, he explains; “Naturally, bad bacteria include pathogens, like Clostridium difficile, that can come to proliferate and cause problems. A healthy microflora can work to prevent their growth. That’s why antibiotic acquired diarrhea (AAD) occurs – the normal “good” microbiota are disturbed or altered due to the antibiotics, and hence the pathogen can proliferate. Another thing that could make a bacteria “bad” is any bacteria that could escape and get into the blood stream.”

Does taking probiotics (either in yogurts or pill form) help?

Research shows that taking probiotics to help treat antibiotic associated diarrhea or infectious diarrhea can result in shortening the duration of symptoms experienced by one day.  The American Academy of Pediatrics supports the recommendation of Lactobacillus rhamnosus GG supplementation early in the course of acute infectious diarrhea to reduce symptom duration.  This particular probiotic can be found in pill form over the counter in products like Culturelle, Centrum ProNutrients Probiotic, and Solgar brand probiotics.  Regarding antibiotic associated diarrhea (AAD), scientists used the probiotic mixture currently marketed as DanActive (Dannon) in the United States and found that it significantly reduced diarrhea in hospitalized patients.  There is research to suggest that probiotics may also help with ulcerative colitis and irritable bowel disease.

“Probiotics are likely to be safe for healthy people; side effects, if they occur at all, consist only of mild digestive symptoms such as gas.  On the other hand, people who have serious underlying medical conditions, such as weakened immune systems, are critically ill, have had surgery, or are sick infants may be at risk for serious side effects, such as dangerous infections and should not take probiotics.”    (Patricia Hibberd, 2015)

Ok, so what about prebiotics?

Prebiotics are nondigestible food ingredients that promote the growth of beneficial microorganisms in the intestines.  On the topic of prebiotics, Dr.  Stefano Guandalini, MD, Section Chief of Pediatric Gastroenterology, Hepatology, and Nutrition and Medical Director of the Celiac Disease Center at the University of Chicago, says “In theory these are a good way of promoting a healthy microflora in your gut, and one would expect beneficial effects, but in reality it has been quite disappointing. There’s not a lot of practical use for prebiotics as we speak, in terms of clinical effectiveness. The only niche in which we found them to be successful is as an additive to formula for premature babies, because human milk actually contains plenty of prebiotics. Other than that, there hasn’t been much practical use. In fact, in our review, we saw that prebiotics have been tried for treating irritable bowel syndrome, but actually with mostly negative results”. Some natural food sources of prebiotics include: garlic, onions, bananas, beans, artichokes, asparagus, bran, legumes, leeks, apples and root vegetables.

If I decide to use probiotics, how much do I need to notice a desired effect?

If using an over the counter pill, follow the instructions on the label, and continue taking them as advised throughout the time an effect is desired ( for example, from the onset of diarrhea, until a few days after the diarrhea has ended.) Otherwise, eating a yogurt, or drinking a kefir once per day should be sufficient according to Dr. Matthew Ciorba.

Product                 Organism(s)                                                Disease/Issue

IBS    Colic   Diarrheal    Ulcerative Colitis

Biogaia             Lactobacillus reuteri                                    *

Culturelle        Lactobacillus GG                                                             *

Florastor          Saccharomyces boulardii (a yeast)                             *

VSL#3               Combination of 8 organisms             *                                            *

Danactive        Streptococcus thermophilus,

Lactobacillus bulgaricus,

and Lactobacillus casei                                                  *

Align                 Bifidobacterium                                   *

This table identifies the specific strains that have been validated through clinical trials and if possible, had their effects reproduced by different groups.  We can see that the list of probiotics that have gone through this process is pretty short.  It doesn’t mean that other preparations don’t work, it just means that they haven’t been scientifically validated as of yet.

Can probiotics really help people to lose weight?

Studies show that taking the right probiotics actually can help people lose weight.  Amazingly enough, one group of researchers actually looked at the effect of ingesting probiotics while maintaining a poor diet.  A very recent study at Virginia Tech investigated how the probiotic VSL#3 affected students fed high fat high calorie diets.  20 men ranging in age from 18 to 30 were fed high fat (55% fat), high calorie (an extra 1000 calories per day) diets for four weeks.  (For the record, it takes approximately 3500 calories to make one pound.  Therefore, by taking in an extra 1000 calories per day, these gentlemen could have gained as much as 8 pounds over the course of this two week trial.)  Half of the participants in this study received a supplement containing the probiotic VSL#3, and the other half received a placebo.  At the end of four weeks, the placebo group gained an average of 5.06lbs, while the probiotic group gained only 3.14lbs.  What’s more is that when these men underwent X-ray scans to determine their body fat mass, it was determined that the probiotic group gained 1.4lbs of body fat while the placebo group gained 2.8lbs.

That’s twice as much body fat gained by the placebo group than by the probiotic group.  Many more studies indicate that probiotics like Lactobacillus and Bifidobacterium also help to reduce fat mass, insulin resistance, and gut inflammation in obese people and in people with type II diabetes.

The research investigating probiotics is so prolific, we are just beginning to scratch the surface of what these little bugs can do.