My Tummy Hurts: What a Groundbreaking 10-Year Study Reveals About Stomach Pain at Every Age
Every parent knows the phrase. It comes at breakfast, at bedtime, before school, and after dinner. Sometimes with tears, sometimes matter-of-factly, sometimes in a way that is impossible to decode: my tummy hurts.
For kids, chronic stomach pain is often dismissed as anxiety, poor eating, a plea for attention, or just not knowing how to treat. For adults, it becomes a quality-of-life issue that gets managed with antacids and workarounds rather than ever really being understood. Stomach pain is so common across every age group that we have almost normalized it. But new research published in 2026 is challenging that normalization in a powerful way, and the implications reach far beyond childhood.
WHAT THE RESEARCH SHOWS
- A landmark 2026 study found that infants given L. reuteri DSM 17938 were 84 percent less likely to develop functional abdominal pain by age 10 than infants given a placebo.1
- In adults with moderate to severe IBS, a combination of L. reuteri DSM 17938 and ATCC PTA 6475 produced significant symptom improvement beginning at week six of a 14-week clinical trial.5
- Both strains have been studied as add-ons to standard H. pylori antibiotic therapy, with research suggesting improved abdominal pain outcomes compared to antibiotics alone.8,9
- Zoguri is the first probiotic on the market to deliver both L. reuteri strains in a fermented yogurt format, which research suggests may support probiotic viability through the digestive tract.11
The Study That Stopped the Gut Health World in Its Tracks
In February 2026, researchers published the results of an extraordinary 10-year follow-up study in the journal Nutrients.1 The original investigation had enrolled 468 healthy infants who received either Limosilactobacillus reuteri DSM 17938 or a placebo during the first three months of life. The probiotic was initially given to examine its effects on infantile colic and early gut comfort. What the researchers discovered a decade later was far more significant than anyone had anticipated.
At age 10, children who had received L. reuteri DSM 17938 as infants had a functional abdominal pain rate of just 13.1 percent. Children who had received the placebo had a pain rate of 80.2 percent. That is an absolute risk reduction of 67.1 percent, and a relative risk of 0.16, meaning the probiotic group was 84 percent less likely to develop functional abdominal pain by their tenth birthday.1
These are not modest numbers. They represent one of the most striking long-term findings in probiotic research to date. The researchers were careful to note the study's limitations, including a 57 percent attrition rate in the follow-up period and the observational nature of the long-term component. They appropriately framed their findings as an association rather than proof of causation. But the magnitude of the difference is difficult to ignore, and it raises a fundamental question: what if the microbiome established in the earliest months of life does have lasting consequences for how the gut processes pain for years to come?
What Functional Abdominal Pain Actually Is
Functional abdominal pain disorders are a category of conditions defined by recurring stomach pain without an identifiable structural cause. In children, they include functional abdominal pain syndrome, irritable bowel syndrome, and functional dyspepsia. These are not imaginary complaints. These are recognized medical conditions that significantly affect a child's quality of life, school attendance, and emotional wellbeing, and they are remarkably common. Worldwide, functional abdominal pain disorders affect an estimated 13 to 38 percent of children, making them among the most prevalent chronic complaints in pediatric medicine.2
In adults, similar disorders affect an estimated 10 to 15 percent of the United States population. Many adults with chronic functional stomach pain report that their symptoms began in childhood, raising the possibility that what happens in the gut during early development has consequences that may extend into adult life.3
From Colic to Chronic Pain: A Story That Starts in Infancy
The 2026 study builds on a body of research showing that L. reuteri DSM 17938 has been evaluated in multiple randomized controlled trials for infant digestive comfort starting in the earliest weeks of life. Infantile colic, characterized by excessive crying and apparent abdominal distress in otherwise healthy babies, affects roughly 20 percent of infants worldwide. A randomized, placebo-controlled trial found that breastfed colicky infants receiving L. reuteri DSM 17938 were more than twice as likely to experience significant relief from crying compared to infants given a placebo. Improvements showed up as early as day seven and held steady through the full study period.4
What the 2026 follow-up study suggests is that the benefit of early L. reuteri DSM 17938 supplementation does not stop when the colic resolves. The babies who received this probiotic in the first three months of life were not just more comfortable as infants. They were dramatically less likely to have a gut that chronically hurt a full decade later. Although the mechanisms are still being studied, researchers propose that early supplementation with L. reuteri DSM 17938 may influence the developing gut microbiome in ways that may help shape how the gut and brain communicate about pain.1
In simpler terms, what happens to the gut microbiome in those early months may set the trajectory for gut function throughout childhood and potentially into adult life.
It Is Not Just for Kids
Research on L. reuteri DSM 17938 for stomach health does not end with childhood studies. A growing body of adult clinical research confirms that this strain, particularly when combined with its partner strain L. reuteri ATCC PTA 6475, has shown meaningful results in clinical research for functional abdominal pain and gut discomfort in adults as well.
A 2024 randomized, double-blind, placebo-controlled trial published in Frontiers in Gastroenterology enrolled 140 adults with moderate to severe irritable bowel syndrome and administered a combination of L. reuteri DSM 17938 and ATCC PTA 6475 alongside standard care for 14 weeks. Beginning at week six, participants in the probiotic group showed significant improvement in IBS symptoms compared to the placebo group. Notably, the most pronounced improvements were in abdominal pain, pain relieved by bowel movements, bloating, gas, and visible distension, the exact symptoms that make functional gut conditions so disruptive to daily life.5
Underlying biology helps explain why these strains work across age groups. L. reuteri DSM 17938 produces substances that may influence the enteric nervous system, modulate the gut immune response, and support the integrity of the gut barrier, the physical lining that keeps gut contents where they belong and prevents the inflammatory signaling that drives pain hypersensitivity. These mechanisms are not unique to the pediatric gut. They are relevant at every age.6
The Hidden Culprit Behind Millions of Stomach Problems: H. pylori
Not all chronic stomach pain is functional. For a significant portion of people, the source is a bacterial infection that most have never heard of, or if they have, assumed it only affected other people.
Helicobacter pylori is a spiral-shaped bacterium that lives in the lining of the stomach. According to recent epidemiological data, around one-third of adults in the United States show evidence of current or past H. pylori infection, with higher rates in certain demographic groups.7 Most people with H. pylori have no symptoms for years or sometimes even decades. But when it does cause problems, it is a serious cause of persistent stomach pain, nausea, bloating, chronic indigestion, peptic ulcers, and in some cases a precursor to more serious gastric disease.
Signs That May Be Worth a Conversation with Your Healthcare Provider
If you have been dealing with any of the following on a recurring basis, H. pylori infection may be worth discussing with your healthcare provider:
- Recurring pain or pressure in the upper stomach
- A burning sensation in the stomach, especially between meals or on an empty stomach
- Persistent nausea without an obvious cause
- Bloating and frequent belching
- Chronic indigestion that does not respond to dietary changes
- Unexplained loss of appetite
Only a healthcare provider can diagnose H. pylori infection. A simple breath test or stool antigen test is typically used to confirm it.
Standard treatment for H. pylori requires a combination of antibiotics and acid-reducing medications, typically prescribed as a 10 to 14-day regimen. Eradication is effective in many cases, but the treatment is not always easy to tolerate. Antibiotic-associated side effects, including nausea, diarrhea, and altered gut flora are among the most common reasons people struggle to complete the full course of treatment.
This is where the research on L. reuteri becomes particularly relevant for adults dealing with H. pylori. A body of clinical research has explored the role of the two L. reuteri strains found in Zoguri's formula, DSM 17938 and ATCC PTA 6475, as add-ons to standard H. pylori eradication therapy. In one randomized, double-blind, placebo-controlled study, researchers observed a higher H. pylori eradication rate among patients receiving the probiotic combination alongside antibiotic treatment compared to those on antibiotics alone, 75 percent versus 65.9 percent.8 Across the literature, the combination has also been shown to reduce antibiotic-associated side effects and meaningfully improve abdominal pain. In one placebo-controlled trial, 42 percent of patients receiving the probiotic combination reported improvement in abdominal pain, compared to just 19 percent in the control group.9
H. pylori infection requires proper medical diagnosis and treatment, and probiotics alone are not a substitute for the antibiotic therapy your healthcare provider can prescribe. But the research suggests that adding L. reuteri DSM 17938 and ATCC PTA 6475 to that treatment protocol may help the therapy work better and make the process more tolerable. If you suspect H. pylori or have been diagnosed with it, that conversation is definitely worth having with your healthcare provider.
How Zoguri's Seven-Strain Formula Addresses the Full Picture
Stomach pain is rarely one-dimensional. Whether it originates in gut dysbiosis, visceral hypersensitivity, gut barrier weakness, immune dysregulation, or the presence of a bacterial infection like H. pylori, the microbiome is involved at every level. That is what makes a comprehensive, multi-strain probiotic approach relevant to this conversation.
Zoguri's formula centers on both keystone L. reuteri strains, DSM 17938 and ATCC PTA 6475, which together have shown the most strain-specific research relevant to functional abdominal pain, IBS symptom relief, and H. pylori add-on support. The five supporting strains, S. thermophilus, L. bulgaricus, L. acidophilus, Bifidus, and L. casei, each contribute to the overall gut environment in ways that help support digestive comfort. L. acidophilus and L. casei have both been studied for their role in supporting gut barrier integrity and reducing intestinal inflammation. Bifidus plays a foundational role in immune tolerance in the gut. S. thermophilus and L. bulgaricus, the traditional fermentation cultures, support the overall microbial ecosystem that helps keep digestion smoother and less reactive.10
Delivered in a yogurt-based, fermented format, these strains arrive in the gut embedded in the food matrix they were grown in, which research suggests may support their viability through the digestive tract better than many encapsulated formats.11
What This Means for Families and Adults Alike
If you have a child who complains regularly about stomach pain, the 2026 research offers a genuinely hopeful new context. Early gut support may not just help at that moment. It may help shape how the gut responds to the world for years to come.
If you are an adult who has been managing chronic stomach pain, digestive unpredictability, or the aftermath of H. pylori treatment, the research on these specific strains offers a scientifically grounded rationale for exploring probiotic support as part of your approach. Not as a cure, and not as a replacement for medical care, but as a meaningful way to support the gut environment that underlies so much of how your stomach feels every day.
The phrase my tummy hurts deserves to be taken seriously, whether it comes from a six-year-old at the breakfast table or an adult who has been living with it for years. The science is building a compelling case where answers may be closer than we think, and that they may begin, at every age, with the bacteria you carry in your gut.