Researchers in Indonesia studied how the bacteria living in our stomachs might be connected to belly fat. They looked at 46 adults and found that people with more belly fat had different types of gut bacteria compared to those without belly fat. Interestingly, one type of bacteria called Prevotella_9 copri showed a connection to belly fat in this Indonesian population, but this finding was different from what scientists found in other countries. This suggests that the bacteria in our guts might work differently depending on where we live and what we eat. The researchers say we need bigger studies to understand if these bacteria actually cause belly fat or if it’s just a coincidence.

The Quick Take

  • What they studied: Whether the types of bacteria living in people’s stomachs are different in people with belly fat versus people without belly fat, and how this connects to what they eat
  • Who participated: 46 adults living in Semarang, Indonesia, between ages 20 and 50 years old. Half had belly fat (abdominal obesity) and half did not.
  • Key finding: People with belly fat had significantly more visceral fat (the dangerous fat around organs) and showed different gut bacteria patterns. One specific bacteria type called Prevotella_9 copri was linked to belly fat in this Indonesian group, which is different from what other countries’ studies found.
  • What it means for you: This research suggests that gut bacteria may play a role in belly fat development, but it’s still early-stage research. The findings may be unique to Indonesian populations and their eating habits. Don’t make major diet changes based on this alone—talk to your doctor about belly fat concerns.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time of 46 Indonesian adults and compared two groups: those with belly fat and those without. The researchers measured how much fat each person had around their belly and organs, asked them about their diet, and collected stool samples to identify what bacteria lived in their stomachs.

The scientists used a special DNA test called 16S rRNA gene sequencing to identify the different types of bacteria in each person’s gut. This is like taking a fingerprint of all the bacteria present. They then looked for patterns—did certain bacteria appear more often in people with belly fat? Did the amount of protein, carbs, or fat someone ate affect which bacteria they had?

This type of study is useful for finding connections between things, but it can’t prove that one thing causes another. It’s like noticing that people who wear winter coats are cold—the coat and cold go together, but we can’t say the coat caused the cold.

Cross-sectional studies are good for spotting patterns and generating new questions for future research. This approach was important here because very little research had looked at gut bacteria and belly fat specifically in Indonesian populations. Since Indonesia has unique dietary patterns and food traditions, studying local populations helps scientists understand if findings from other countries apply everywhere or if each region has its own patterns.

This is a small pilot study with only 46 people, which is a limitation. The researchers themselves note that larger studies are needed to confirm these findings. The study was well-designed with proper measurements and modern DNA testing methods, which is good. However, because it’s small and only done once in one location, we should be cautious about applying these results to all Indonesians or other populations. The fact that their findings differed from other countries is interesting but needs more investigation to understand why.

What the Results Show

The main finding was that people with belly fat had much higher levels of visceral fat (the dangerous fat around organs) compared to those without belly fat: 12.32% versus 6.96%. This confirms that belly fat is a real and measurable difference between the two groups.

When looking at gut bacteria, the researchers found that one type of bacteria called Prevotella_9 copri showed a connection to visceral fat in this Indonesian population. However, this connection was weak (the statistical measure was r = 0.206, p = 0.169), meaning it’s not a strong relationship and could partly be due to chance.

What makes this interesting is that other studies done in different countries found different patterns with this same bacteria. In Semarang, Indonesia, Prevotella_9 copri was linked to more belly fat, but in other places, this bacteria didn’t show the same connection. This suggests that the relationship between gut bacteria and belly fat might depend on where people live, what they eat, and possibly their genetics.

The researchers also looked at whether the amount of protein, carbohydrates, and fat people ate affected their gut bacteria composition. While they measured this information, the abstract doesn’t detail all these secondary findings, suggesting the main focus was on the Prevotella_9 copri connection. Future publications from this research may reveal more about how diet influences these bacteria patterns.

Previous research in other countries has shown that certain bacteria are linked to obesity, but the specific bacteria and their patterns vary by location. This Indonesian study adds important information by showing that the same bacteria (Prevotella_9 copri) behaves differently in different populations. This is a valuable finding because it means scientists can’t just copy results from one country and assume they apply everywhere. It highlights that we need research from many different populations to truly understand how gut bacteria and belly fat are connected.

The biggest limitation is the small sample size of only 46 people. This makes it harder to be confident in the findings and easier for random chance to affect the results. The study was done only in one city (Semarang) in one country (Indonesia), so we don’t know if these findings apply to other Indonesian cities or other populations. Because this is a cross-sectional study (a snapshot in time), we can’t tell if the bacteria differences cause belly fat, if belly fat causes bacteria changes, or if something else causes both. The researchers themselves acknowledge these limitations and call for larger, longer-term studies to confirm their findings.

The Bottom Line

Based on this research alone, there are no specific recommendations to follow. This is early-stage research that suggests gut bacteria may be involved in belly fat development, but much more evidence is needed. General health recommendations remain: maintain a balanced diet, exercise regularly, and talk to your doctor about belly fat concerns. If you’re interested in gut health, eating fiber-rich foods and diverse plant-based foods generally supports healthy gut bacteria, but this study doesn’t provide specific guidance.

This research is most relevant to people concerned about belly fat and metabolic health, researchers studying obesity and gut bacteria, and healthcare providers in Indonesia and similar populations. People with family history of heart disease or metabolic syndrome may find this interesting since belly fat is linked to these conditions. However, this is preliminary research, so it shouldn’t change anyone’s current health practices without consulting their doctor.

This is not a study about interventions or treatments, so there’s no timeline for seeing benefits. It’s a research study that identifies a potential connection. If future research confirms these findings and develops treatments based on them, it could take 5-10 years or more before practical applications become available.

Want to Apply This Research?

  • Track waist circumference weekly and note any dietary changes. Measure waist circumference at the narrowest point between ribs and hip bones. Record in centimeters or inches to monitor trends over time.
  • Increase dietary fiber intake by adding more vegetables, fruits, and whole grains to meals. Log daily fiber intake (target 25-30 grams) and note any changes in digestion or energy levels over 4-8 weeks.
  • Create a long-term tracking dashboard showing waist circumference trends, dietary patterns (especially fiber and macronutrient balance), and general wellness markers like energy and digestion quality. Review monthly to identify patterns between diet and body composition changes.

This research is a small pilot study and should not be used to diagnose, treat, or prevent any medical condition. The findings are preliminary and need confirmation through larger studies. If you have concerns about belly fat, weight gain, or metabolic health, please consult with a qualified healthcare provider or registered dietitian. This article is for educational purposes only and does not replace professional medical advice. Individual results may vary based on genetics, lifestyle, and other factors not studied here.