Taking Probiotics but Still Getting Sick After Gluten – Advice?

[Xravith]

Hello,
I've been diagnosed with IBS since I was little. I’ve visited many doctors because my intestines have always been very reactive to food. I have chronic swelling, and I struggle to gain weight.

This year has been worse than others: I started noticing fatigue, loss of muscle mass, and many digestive problems, especially after consuming products with gluten. My doctor suggested that this might be due to some imbalance of gut bacteria, so I started taking Bifidobacterium Infantis supplements.

However, my symptoms have been getting worse every day. I experience nausea, frequent abdominal pain, migraines, and palpitations after eating. I had these symptoms before, but now they are more intense. I thought I might have Non-celiac gluten sensitivity or Celiac Disease, so I took a home test for Celiac, and it came out negative (though there may have been an error—I was nervous and accidentally contaminated the sample with air bubbles).

Based on your experiences, should I pursue further medical exams for Celiac? I’m worried about being underweight and about my blood test results, which, even if still within normal ranges, have been declining each year.

[Scott Adams]

Based on what you've described, it is absolutely crucial that you pursue further medical exams for Celiac Disease and related conditions with a gastroenterologist. Your symptoms—especially the worsening fatigue, loss of muscle mass, neurological symptoms like migraines, and palpitations, coupled with being underweight—are significant red flags that extend beyond typical IBS. The negative home test is not reliable, particularly given your concern about sample contamination and the fact that you were likely not consuming sufficient gluten at the time for the test to be accurate, which is a common issue. While probiotics like Bifidobacterium Infantis can support gut health, they cannot resolve an autoimmune response to gluten or heal intestinal damage caused by Celiac Disease. Your declining blood test results, even if still "in range," further indicate a trend that needs a doctor's investigation. Please do not hesitate to seek a specialist; a formal diagnosis is the first step toward getting the correct treatment, allowing your body to heal, and finally addressing your weight and overall health concerns.

This article might be helpful. It breaks down each type of test, and what a positive results means in terms of the probability that you might have celiac disease. One test that always needs to be done is the IgA Levels/Deficiency Test (often called "Total IGA") because some people are naturally IGA deficient, and if this is the case, then certain blood tests for celiac disease might be false-negative, and other types of tests need to be done to make an accurate diagnosis. The article includes the "Mayo Clinic Protocol," which is the best overall protocol for results to be ~98% accurate.

 

 

[trents]

As Scott said, in order for celiac disease testing to be valid, you need to be eating generous amounts of gluten on a regular basis for weeks or months before the blood draw. The blood tests are designed to detect antibodies that the immune system produces in response to the ingestion of gluten. It takes time for them to build up in the blood to detectable levels.

Edited October 7, 2025 by trents

[Xravith]

Thank you, really. 

I took a test for DGP-IgA and DGP-IgG. Effectively, it is not enough to discard Celiac Disease. I was consuming gluten until then, I only started gluten-free some days ago, when the symptoms became horrible and now I feel considerably better, which is a second confirmation that gluten is the main problem.

It's been more than 4 years I have the same suspect, when I first thought gluten was causing me problems, I made a gluten-free diet for a year, I felt really good as never before. However, neither I or my parents were well informed about Celiac disease, so none of us tried to make further exams. My father suffer digestive problems and other members of my family as well. Unfortunately, no one have ever been tested for Celiac disease.

I'll have to restart eating gluten in the next weeks, so I can make a serious blood test in laboratory, hopefully between two or three months.

[trents]

The blood tests you had done are not the main ones. The two main ones are the "Total IGA" (to check for IGA deficiency) and the "TTG-IGA".

Current guidelines for the "gluten challenge" when people have been gluten free for a significant time period are the daily consumption of at least10g of gluten (about the amount in 4-6 slices of wheat bread) for at least two weeks leading up to the day of the blood draw. That should give you some perspective.

[knitty kitty]

On 10/7/2025 at 11:49 AM, Xravith said:

...swelling, and I struggle to gain weight.

This year has been worse than others: I started noticing fatigue, loss of muscle mass, and many digestive problems, especially after consuming products with gluten.

However, my symptoms have been getting worse every day. I experience nausea, frequent abdominal pain, migraines, and palpitations after eating. I had these symptoms before, but now they are more intense. 

Welcome to the forum, @Xravith.

I experienced similar symptoms before my diagnosis.  Mine were due to the loss of vitamins and minerals, essential nutrients we must get from our food.  With Celiac Disease, the intestinal lining, made up of thousands of villi, gets damaged and cannot absorb essential vitamins and minerals, especially the eight B vitamins. 

The loss of Thiamine B 1 can cause muscle loss, inability to gain weight, edema (swelling), fatigue, migraines and palpitations.  Low thiamine can cause Gastrointestinal Beriberi with symptoms of nausea, abdominal pain and bloating.  

Thiamine is only stored for a couple of weeks, so if you don't absorb enough from food daily, as the thiamine deficiency worsens physical symptoms gradually worsen.  If you're eating lots of carbs (like gluten containing foods usually do), you need more thiamine to process them (called high calorie malnutrition).  Thiamine works with all the other B vitamins, so if you're low in one, you're probably getting low in the others, too, and minerals like iron, magnesium, zinc, and calcium, as well as Vitamin D.. 

Talk to your doctor about checking for nutritional deficiencies.  Most doctors rarely recognize vitamin deficiency symptoms, especially in thiamine.

Get a DNA test to see if you carry any Celiac genes.  If you do not have genetic markers for Celiac, it's probably IBS.  If you do have genetic markers for Celiac, it's probably Celiac.  I was misdiagnosed with IBS for years before my Celiac diagnosis.  

Keep us posted on your progress.

P. S. Deficiency in thiamine can cause false negatives on antibody tests, as can diabetes and anemia.  

Edited October 9, 2025 by knitty kitty
Added Post Script

[dublin555]

If you're still eating gluten, I'd ask your doctor for a proper blood panel, specifically tissue transglutaminase IgA, total IgA, and maybe deamidated gliadin peptide tests. Home tests aren't always reliable.

Since you mentioned fatigue and weight loss, it's worth checking for nutrient deficiencies too (iron, B12, vitamin D). Even if it's not Celiac, those labs can point to malabsorption issues.

[Xravith]

13 hours ago, knitty kitty said:

Welcome to the forum, @Xravith.

I experienced similar symptoms before my diagnosis.  Mine were due to the loss of vitamins and minerals, essential nutrients we must get from our food.  With Celiac Disease, the intestinal lining, made up of thousands of villi, gets damaged and cannot absorb essential vitamins and minerals, especially the eight B vitamins. 

The loss of Thiamine B 1 can cause muscle loss, inability to gain weight, edema (swelling), fatigue, migraines and palpitations.  Low thiamine can cause Gastrointestinal Beriberi with symptoms of nausea, abdominal pain and bloating.  

Thiamine is only stored for a couple of weeks, so if you don't absorb enough from food daily, as the thiamine deficiency worsens physical symptoms gradually worsen.  If you're eating lots of carbs (like gluten containing foods usually do), you need more thiamine to process them (called high calorie malnutrition).  Thiamine works with all the other B vitamins, so if you're low in one, you're probably getting low in the others, too, and minerals like iron, magnesium, zinc, and calcium, as well as Vitamin D.. 

Talk to your doctor about checking for nutritional deficiencies.  Most doctors rarely recognize vitamin deficiency symptoms, especially in thiamine.

Get a DNA test to see if you carry any Celiac genes.  If you do not have genetic markers for Celiac, it's probably IBS.  If you do have genetic markers for Celiac, it's probably Celiac.  I was misdiagnosed with IBS for years before my Celiac diagnosis.  

Keep us posted on your progress.

P. S. Deficiency in thiamine can cause false negatives on antibody tests, as can diabetes and anemia.  

Thank you for the advice. I’ve actually never checked for nutritional deficiencies, but for as long as I can remember, I’ve always taken vitamin and mineral supplements — otherwise my symptoms get worse.

This week I stopped eating gluten to confirm whether my symptoms are really caused by it. Starting next week, I’ll reintroduce gluten — it’s sad to go back to how I was before — but at least I’ll be able to take the necessary tests properly.

I think the diagnostic process will be long, but at least I’m happy that I finally decided to address this doubt I’ve had for years.

[knitty kitty]

Symptoms that get worse if you don't supplement is a sign of malabsorption, possibly due to Celiac disease.

Blood tests for nutritional deficiencies are not very accurate, and should be done when you have been off of supplements for eight to twelve weeks, otherwise the vitamin supplements you've taken will be measured.  The blood circulation system is a transportation system.  It transports the vitamins you've absorbed around the body, but blood tests don't give an accurate picture of the vitamin and mineral stores inside organs and tissues where they are actually used.  You can have "normal" blood levels but still have deficiencies.  This is because the brain demands stored nutrients be put into the blood stream to supply important organs, like the brain and heart, while other organs do without.  

If you are taking Thiamine Mononitrate in your supplements, you are probably low in thiamine.  Thiamine Mononitrate is used in many supplements because it won't break down sitting on a shelf.  This also means Thiamine Mononitrate is difficult for the body to utilize.  Only thirty percent of Thiamine Mononitrate on the label is absorbed and even less is able to be utilized by the body.  A different form of Thiamine called Benfotiamine has been shown to promote intestinal healing.  

Talk to your doctor about doing a genetic test to look for Celiac markers.  

I'm concerned that if you do a gluten challenge (10 grams of gluten per day for a minimum off two weeks) in your weakened state, the nutritional deficiencies will become worse and possibly life threatening.  

[Xravith]

On 10/11/2025 at 7:59 PM, knitty kitty said:

Symptoms that get worse if you don't supplement is a sign of malabsorption, possibly due to Celiac disease.

Blood tests for nutritional deficiencies are not very accurate, and should be done when you have been off of supplements for eight to twelve weeks, otherwise the vitamin supplements you've taken will be measured.  The blood circulation system is a transportation system.  It transports the vitamins you've absorbed around the body, but blood tests don't give an accurate picture of the vitamin and mineral stores inside organs and tissues where they are actually used.  You can have "normal" blood levels but still have deficiencies.  This is because the brain demands stored nutrients be put into the blood stream to supply important organs, like the brain and heart, while other organs do without.  

If you are taking Thiamine Mononitrate in your supplements, you are probably low in thiamine.  Thiamine Mononitrate is used in many supplements because it won't break down sitting on a shelf.  This also means Thiamine Mononitrate is difficult for the body to utilize.  Only thirty percent of Thiamine Mononitrate on the label is absorbed and even less is able to be utilized by the body.  A different form of Thiamine called Benfotiamine has been shown to promote intestinal healing.  

Talk to your doctor about doing a genetic test to look for Celiac markers.  

I'm concerned that if you do a gluten challenge (10 grams of gluten per day for a minimum off two weeks) in your weakened state, the nutritional deficiencies will become worse and possibly life threatening.  

Yes, you are right. Indeed, I’ve been feeling anemic since the beginning of this week, and today I felt horrible during a lecture at the university, I was trembling a lot and felt all my body incredibly heavy, so I had to come back home. I’ll do a blood test tomorrow, but I’m just worried about the possibility of it coming back negative. I’ve been eating two cookies in the morning as my only source of gluten over the past two weeks—could that affect the final result?

[knitty kitty]

@Xravith,

How are you doing?  

Two cookies are not enough.  For testing, you need to be eating a minimum of ten grams of gluten for two weeks minimum before testing for Celiac antibodies.  Ten grams of gluten is roughly five or six slices of gluten containing bread per day for two weeks minimum.

Breads that contain lots of gluten typically have large bubbles formed by gases escaping during baking.  Gluten helps form those bubbles of trapped gases, like a balloon.  Artisan breads, and thick, chewy pizza crust are good examples.  Look at the size of the bubbles in cakes and cookies.  Small bubbles, so not lots of gluten in them.  You'd have to eat tons of cookies to get ten grams.  

Antibodies are made in the small intestine. If you eat at least TEN grams of gluten for at least two weeks, then there will be sufficient antibodies to move into the bloodstream, which can be measured in antibody tests.  

If you eat less than ten grams of gluten daily, you will get celiac symptoms, but not enough antibodies will get into the bloodstream to be measured, resulting in false negatives.  Anemia, diabetes, and thiamine deficiency can also affect testing, resulting in false negatives.

Since you are having such difficulty consuming sufficient quantities of gluten, you should consider getting a genetic test done.  You do not have to eat gluten to have a genetic test done.  Celiac is inherited.  It's in your genes.  Genes don't change whether you eat gluten or not.  A genetic test looks for the most common known Celiac genes.  If you do not have the genes, your doctor can look for other health conditions that can be causing symptoms.  If you do have Celiac genes, you can assume that those genes are actively causing symptoms.  An endoscopy to check for the amount of intestinal damage caused by Celiac Disease is usually done.  

You should also be checked for nutritional deficiencies.  Ask for an Erythrocyte Transketolace Activity test, which checks for Thiamine deficiency.  Thiamine, Vitamin B 1, is one of the eight essential B vitamins.  Thiamine can become low quickly because our bodies use so much of it everyday.  If we're not replenishing Thiamine daily from our diet or because of malabsorption, we can become seriously ill.  Same with the other seven B vitamins.  

Doctors are not familiar with nutritional deficiency symptoms as can occur in Celiac disease.  Please get checked for nutritional deficiencies.  Ask for the Erythrocyte Transketolace Activity test soon.

Please let us know how you are doing.  

[Xravith]

@knitty kitty 

Thank you very much for the advice. I did the exam this morning, my doctor actually suggested me to take something called "Celiac duo test" in which I first do the genetic test and if it's positive, then I'll have to do the antigen blood test. I have to attend 1 month until my results are ready, so I have some weeks to increase the amount of gluten I eat daily. It will be hard because my health is not the best right now, but I also did a blood test to cheek my nutritional deficiencies. The results will arrive on Tuesday, so I can ask my doctor what should I do to control my symptoms and blood levels during this month. For now I'm resting and paying attention to what I eat— at least I don’t look like a vampire who just woke up, like I did yesterday.

I'm still scared because is the first time I've felt this sick, but this is the right moment to turn things around for the better. 

I realized that if I eat gluten at lunch I cannot finish the day properly, I become severely tired and sometimes my stomach hurts a lot - let's not talk about the bloating that starts later. Do you think is it ok to eat gluten just in the morning, like some cookies and slices of bread for breakfast? 

[knitty kitty]

Some people prefer eating gluten before bed, then sleeping through the worst symptoms at night.  You might want to try that and see if that makes any difference.  

Several slices of toast for breakfast sounds okay.  Just try to work up to the Ten grams of gluten.  Cookies might only have a half of a gram of gluten.  The weight of the whole cookie is not the same as the amount of gluten in it.  So do try to eat bread things with big bubbles, like cinnamon rolls.  

Yeah, I'm familiar with the "death warmed over" feeling.  I hope you get the genetic test results quickly.  I despise how we have to make ourselves sick to get a diagnosis.  Hang in there, sweetie, the tribe is supporting you.  

[Xravith]

My genetic test results have arrived - I’m homozygous for DQB1*02, meaning I have HLA-DQ2. I’ve read that this is one of the genes most strongly associated with celiac disease, and my symptoms are very clear. I’m relieved that the results finally arrived, as I was getting quite worried since my symptoms have been getting worse. Next step, blood test.

What do these results imply? What should I tell my family? I’m concerned that this genetic predisposition might also affect other family members.

[trents]

I assume that you already know that genetic testing for celiac disease cannot be used to confirm a celiac diagnosis. About 40% of the general population has the genetic potential to develop celiac disease but only about 1% actually develop celiac disease. It can be used to rule out celiac disease with a high degree of confidence, however, in the case where the genetic testing is negative for the genes.

Until and unless you are actually diagnosed with celiac disease I would not raise this as an issue with family. However, if you are diagnosed with celiac disease through blood antibody testing and/or endoscopy with positive biopsy I would suggest you encourage first degree relatives to also purse testing because there is a significant chance (somewhere betwee 10% and almost 50%, depending on which studies you reference) that they will also have or will develop active celiac disease. Often, there are symptoms are absent or very minor until damage to the small bowel lining or other body systems becomes significant so be prepared that they may blow you off. We call this "silent celiac disease". 

[Xravith]

I'm very confused...

My blood test came out negative, I checked all antibodies. I suppose my Total IgA levels are normal (132 mg/dl), so the test should be reliable. Still, I'm not relieved as I can't tolerate even a single biscuit. I need to talk to my doctor about whether a duodenal biopsy is necessary.

But it is really possible to have intestinal damage despite having a seronegative results? I have really strong symptoms, and I don't want to keep skipping university lectures or being bedridden at home.

[Scott Adams]

I will assume you did the gluten challenge properly and were eating a lot of gluten daily for 6-8 weeks before your test, but if not, that could be the issue.

You can still have celiac disease with negative blood test results, although it's not as common: 

Clinical and genetic profile of patients with seronegative coeliac disease: the natural history and response to gluten-free diet:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5606118/ 

Seronegative Celiac Disease - A Challenging Case:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9441776/ 

Enteropathies with villous atrophy but negative coeliac serology in adults: current issues:
https://pubmed.ncbi.nlm.nih.gov/34764141/ 

Approximately 10x more people have non-celiac gluten sensitivity than have celiac disease, but there isn’t yet a test for NCGS. If your symptoms go away on a gluten-free diet it would likely signal NCGS.

[trents]

NCGS does not cause damage to the small bowel villi so, if indeed you were not skimping on gluten when you had the antibody blood testing done, it is likely you have celiac disease.