Everyone has heard about probiotics – but how do you know which are friendly and helpful, and which are UN-friendly and detrimental? Not all probiotics are all friendly, all the time. The microbes in probiotics vary in the sorts of tasks they do for us – so, depending on when, what, and how you’re using them, they can be a big help or a big fail.

Probiotics are bacteria or yeast supplements, in case you missed the memo, that you can buy and eat as a supplement. There are powders, capsules, chewables, probiotic foods and drinks… you  name it, it’s out there. The idea is to help populate your intestine with the types of bacteria that keep you healthy. Turns out we really need bacteria, viral exposures, and even some fungal (yeast) species to co-exist with us. These help our immune systems stay robust and direct traffic – especially at the gut wall lining, where our insides meet the outside world.

What’s in a human gut biome, and what species of microbes do what, is a burgoening area of study in medicine and health. While the old paradigm believed in a kill-all-germs and take-no-prisoners approach to immune health, the new paradigm has noticed that this doesn’t really work – because it makes people have more allergy, more inflammatory conditions, more autoimmune problems, and possibly, more susceptibility to serious conditions later in life, like cancer. A great example of this is how exposure to infections like measles and chickenpox in childhood protect us later on from certain cancers or shingles. But, now that we so enthusiastically use antibiotics, vaccines, and cleansers to keep germs at bay, we’ve really altered our human immune-scape!

Enter probiotics. Using these really can help many conditions, symptoms, and problems – from asthma and allergies to colitis or obesity.

But what if you use them and your child feels worse?

You may be using the wrong probiotic at the wrong time for the job.

One of the most-often misused strains I encounter in my pediatric nutrition practice is Saccharomyces boulardii. “Sacc B” for short, this is actually a strain of yeast (not bacteria) that has shown some action against tough infections like Clostridia difficile (“C diff”), which has become antibiotic-resistant. C diff has become so resistant to antibiotics that the FDA even approved use of fecal transplants to fight it, so any tools to fight it are worth exploring. Sacc B has been shown to reduce symptoms of irritable bowel, inflammatory bowel, and even Candida infection. Sounds great, right?

But it can make your child feel sick and may trigger symptoms like diarrhea, nausea, bloating, picky appetite or rashes if you use it for too long (more than a month). If your child has antibody reactions to Candida or other Saccharomyces species, then using Sacc B may fail – because the body may attack the Sacc B with an immune response. Cross reaction can occur here, as Candida and Saccharomyces – though they are different species and strains – are all in the fungal family. And that can make Sacc B backfire for your child.

Solution? Withdraw the Sacc B if your child is feeling worse on it; or, don’t use it at all until you screen for antibodies (IgG/M/A) to Saccharomcyes cerevisaie and Candida species. You can also run a stool test for microbiology of these species, which should not be found in excess on your child’s sample.

If you use Sacc B, use it in short bursts, say 3 weeks at a time. Look for improvement then rotate off the Sacc B to mixed Lactobacillus and Bifido strain product, or a spore probiotic with Bacillus species. If no improvement, get professional guidance.

Another frequent fail in supplementing probiotics is using them when your child has small intestine bacterial overgrowth (SIBO) or small intestine fungal overgrowth (SIFO). Symptoms of SIBO and SIFO are similar to symptoms of other GI problems – which leads many parents to give probiotics a try. But, these can make SIBO or SIFO symptoms worse, and fast. A healthy small intestine (which is the first part of the intestine after the stomach) contains a lot fewer bacteria and microbes than the large intestine or colon (further down the pipe). Too much microbial action in the upper part feels awful. This is why kids with SIBO or SIFO often don’t like eating, are very picky, struggle with the slightest variations in food textures, or are even averse to feeding themselves. They may claim to be full when they’ve eaten very little. Add some multistrain probiotics, and this can make it all feel worse.

Solution: If your child is old enough to tolerate a SIBO breath test, you may wish to do this – but, I generally don’t use this test, because it is a tough test for a child to endure, especially if they do have SIBO! Your GI doctor may offer it, and you can ask about how to get your child through the test. If positive, you will need to address this before advancing a probiotic regimen. SIBO and SIFO can be helped with herbal supports and may not necessarily need antibiotic treatment. Once you do eradicate the SIBO or SIFO, single strain products at lower potencies can be helpful, such as Lactobacillus rhamnosus or reuteri at 20 billion CFU per day or less.

Now and then I’ll encounter a child who is downright over-dosed on probiotics by a well meaning parent. Many of us have felt enthusiastic about fermented foods like kombucha, sauerkraut, or kimchee, but overdoing it can create symptoms you’re trying to correct, like gas, bloating, pain, or food refusal. If you’re using these daily for your kids but they aren’t thriving with comfortable appetites and eliminations, revisit this strategy. I like to use a GI MAP PCR DNA stool screen as well as a stool microbiology test to look at what is going on. Sometimes a less aggressive strategy is better, and you can start by simply withdrawing fermented foods or probiotic supplements for a week or so, then resume at smaller doses. You may find your child simply doesn’t need so much probiotic supplementation, from any source.

Lastly, don’t confuse probiotics with pre-biotics. Pre-biotics are starches that friendly bacteria can ferment for us. Some kids (especially with FPIES) don’t tolerate pre-biotic supplements very well, because they may be high in FODMAPs. If you’ve chosen a product that has ingredients like inulin, chicory, galactic-oligosaccharides, cellulose, or maltodextrin, or if the label says “prebiotics”, take note – this may not be the one for your child. You can buy probiotics that omit these ingredients from brands like GutPro or Custom Probiotics.

The choices are dizzying in the world of probiotics, but the good news is there is probably a product that can help your child with appetite, eliminations, and more. If you’d like help, work with me to look deeper into what your child’s solutions might be.