Research shows that eating more processed meats, drinking diet sodas, and consuming alcohol is linked to higher cholesterol and changes in gut inflammation markers in overweight and obese adults. According to Gram Research analysis of this 633-person study, people with the highest adherence to this dietary pattern had significantly elevated total cholesterol and different levels of gut-related proteins (LPS and NGF) that indicate inflammation. While the study demonstrates these associations, it cannot prove the diet directly causes these changes, and researchers emphasize that prospective studies are needed to confirm whether reducing these foods would improve health outcomes.
A new study of 633 overweight and obese adults found that eating more processed meats, drinking alcohol, and consuming artificially sweetened beverages—called the “sulfur microbial diet”—was linked to changes in gut bacteria and inflammation markers. According to Gram Research analysis, people who followed this eating pattern more closely had higher cholesterol levels and different levels of gut-related proteins that affect inflammation and brain health. While the study shows these foods may influence how our gut bacteria work, researchers emphasize this is a snapshot study and can’t prove the diet directly causes these changes. More research is needed to understand if changing these eating habits would improve health.
Key Statistics
A 2026 cross-sectional study of 633 overweight and obese adults found that higher adherence to a diet rich in processed meats, alcohol, and artificially sweetened beverages was significantly associated with elevated total cholesterol levels (adjusted P = 0.028).
According to research reviewed by Gram, participants with the highest sulfur microbial diet scores showed significant differences in circulating LPS concentrations—a marker of gut bacterial toxins and inflammation—with a clear linear trend across diet adherence groups (P for trend = 0.011).
A 2026 study of 633 overweight and obese adults demonstrated that higher consumption of processed meats and diet sodas was linked to altered NGF levels, a protein involved in gut-brain communication and inflammation (adjusted P = 0.047).
Research from 2026 involving 633 participants found no significant associations between the sulfur microbial diet and fasting glucose, insulin, triglycerides, or blood pressure, suggesting the diet’s primary metabolic effects may be specific to cholesterol and inflammatory pathways rather than broad metabolic dysfunction.
The Quick Take
- What they studied: Whether eating a diet high in processed meats, alcohol, and diet sodas is connected to changes in gut bacteria, inflammation, and weight-related health markers in overweight and obese adults.
- Who participated: 633 adults aged 20-60 years with overweight or obesity (BMI of 25 or higher) recruited from nutrition clinics. Researchers looked at what they ate and measured their blood markers and body measurements.
- Key finding: Adults who ate more processed meats, alcohol, and artificially sweetened drinks had higher cholesterol levels and different amounts of gut-related proteins (LPS and NGF) that are linked to inflammation and gut health.
- What it means for you: If you’re overweight or obese, eating less processed meat and diet soda while limiting alcohol may help reduce inflammation and improve cholesterol. However, this study only shows a connection, not proof that changing your diet will definitely help—more research is needed.
The Research Details
This was a cross-sectional study, which means researchers took a snapshot of 633 people at one point in time rather than following them over months or years. Participants filled out detailed food questionnaires about what they typically eat, and researchers calculated a “sulfur microbial diet” score based on how much processed meat, alcohol, and artificially sweetened beverages they consumed. The researchers then divided people into four groups based on their scores—from lowest to highest adherence to this dietary pattern.
Blood samples were collected after fasting (not eating) to measure cholesterol, blood sugar, insulin, and special proteins called LPS and NGF that indicate gut inflammation and gut-brain communication. Researchers also measured body weight, height, and waist size. They used statistical methods to compare the groups while accounting for other factors like age, exercise, and smoking that might affect the results.
This research approach is important because it helps identify dietary patterns that might harm health before doing expensive and time-consuming long-term studies. By measuring specific gut proteins and inflammation markers, researchers can understand the biological pathways—the actual mechanisms—through which certain foods might affect our health. This gives us clues about what to study more carefully in future research.
This study has several strengths: it included a reasonably large sample size (633 people), measured multiple health markers, and used validated questionnaires to assess diet. However, because it’s a cross-sectional study, it only shows associations at one point in time and cannot prove that the diet causes the health changes. People who eat more processed meat might also have other unhealthy habits that explain the findings. The study was conducted in nutrition clinics, so results may not apply to the general population. Researchers acknowledge these limitations and call for prospective studies that follow people over time.
What the Results Show
Adults with the highest adherence to the sulfur microbial diet had significantly higher total cholesterol levels compared to those with the lowest adherence (adjusted P = 0.028). This means the difference is unlikely to be due to chance alone. Additionally, circulating levels of NGF—a protein involved in gut-brain communication and inflammation—differed significantly across the four groups (adjusted P = 0.047).
LPS concentrations, which indicate bacterial toxins in the bloodstream and gut inflammation, also showed significant differences across the diet groups (adjusted P = 0.037), with a clear trend showing higher LPS in people eating more processed meats and diet sodas. Interestingly, the researchers found no significant differences in fasting blood sugar, insulin levels, triglycerides, or blood pressure between groups, suggesting the diet’s effects may be more specific to cholesterol and gut inflammation markers rather than broad metabolic dysfunction.
The findings suggest that the sulfur microbial diet may influence how gut bacteria function, potentially increasing harmful bacterial activity that produces more LPS and affects the gut-brain axis through NGF changes. These alterations could contribute to chronic inflammation, though the study cannot prove this causal relationship.
While not statistically significant, the study observed trends in other metabolic markers that warrant future investigation. The lack of differences in fasting glucose and insulin suggests that this dietary pattern may not immediately affect blood sugar control in overweight and obese adults, though long-term effects remain unknown. The absence of blood pressure differences is also noteworthy, as it suggests the diet’s primary metabolic impact may be on cholesterol and inflammatory pathways rather than cardiovascular regulation.
This study builds on previous research suggesting that processed foods and artificial sweeteners can alter gut bacteria composition. The novel contribution here is measuring specific gut-related biomarkers (LPS and NGF) that connect dietary patterns to inflammation and gut-brain communication. Previous studies have linked processed meat consumption to increased inflammation and metabolic problems, and this research provides a potential mechanism: changes in sulfur-reducing bacteria that produce harmful compounds like hydrogen sulfide and LPS.
The most important limitation is that this is a cross-sectional study—a snapshot in time—so it cannot prove the diet causes these changes. People with higher sulfur microbial diet scores might also smoke more, exercise less, or have other unhealthy habits that explain the findings. The study relied on self-reported food intake, which can be inaccurate. Participants were recruited from nutrition clinics, so they may not represent the general overweight and obese population. The researchers could not measure actual gut bacteria composition, only the biomarkers these bacteria produce. Finally, the study was conducted in a specific population and may not apply to different age groups or ethnic backgrounds.
The Bottom Line
Based on this research, adults with overweight or obesity may benefit from reducing processed meat consumption, limiting artificially sweetened beverages, and moderating alcohol intake. This recommendation has moderate confidence because the study shows associations but cannot prove causation. Increasing whole foods, vegetables, and fiber-rich foods would be a complementary strategy supported by broader nutrition science. Anyone making significant dietary changes should consult with a healthcare provider or registered dietitian.
This research is most relevant to overweight and obese adults concerned about inflammation, cholesterol, and gut health. People with existing metabolic disorders, high cholesterol, or inflammatory conditions may find this particularly relevant. The findings may also interest healthcare providers treating metabolic syndrome. However, this study doesn’t directly apply to people of normal weight, as the research only included overweight and obese participants.
Changes in cholesterol and inflammatory markers typically take 4-8 weeks to become measurable after dietary changes. However, this study cannot predict individual timelines for improvement. Some people may see benefits faster, while others may need longer. Consistent dietary changes over months are usually needed to see meaningful improvements in gut health and metabolic markers.
Frequently Asked Questions
Does eating processed meat really affect your gut bacteria?
Research suggests processed meat consumption alters gut bacteria composition and increases harmful bacterial byproducts like LPS, which trigger inflammation. A 2026 study of 633 overweight adults found higher processed meat intake correlated with elevated LPS concentrations, a marker of gut bacterial toxins. However, this shows association, not definitive proof of causation.
Are diet sodas bad for your gut health?
Artificially sweetened beverages appear to alter gut bacteria and inflammation markers. A 2026 study found that higher consumption of diet sodas (part of the sulfur microbial diet pattern) was associated with elevated cholesterol and different gut-related protein levels. More research is needed to determine if reducing diet sodas directly improves gut health.
How quickly will my cholesterol improve if I stop eating processed meat?
Cholesterol typically begins changing within 4-8 weeks of dietary modifications, though individual timelines vary. This study shows associations but cannot predict personal response rates. Consistent dietary changes over months usually produce measurable improvements. Consult a healthcare provider for personalized expectations based on your health status.
What should I eat instead of processed meat?
Replace processed meats with plant-based proteins like beans, lentils, chickpeas, and tofu, or choose unprocessed poultry and fish. These alternatives support healthier gut bacteria and don’t contain the compounds that trigger the harmful bacterial changes associated with processed meats. Whole foods generally support better metabolic and gut health.
Can this diet cause weight gain?
This study didn’t find significant differences in weight-related markers between groups, though processed meats and sugary/artificially sweetened beverages are typically calorie-dense. The research suggests the diet’s primary effects are on inflammation and cholesterol rather than direct weight gain, but reducing these foods may support weight management through other mechanisms.
Want to Apply This Research?
- Track weekly servings of processed meats, diet sodas, and alcoholic beverages alongside monthly cholesterol and inflammation markers (if available through healthcare provider). Create a goal to reduce processed meat servings by 50% over 8 weeks and eliminate diet sodas, measuring changes in energy levels and digestion.
- Replace one processed meat meal per week with plant-based protein (beans, lentils, tofu). Swap diet sodas for water, herbal tea, or sparkling water with lemon. Set a daily alcohol limit and track adherence. Log these changes in the app with notes about how you feel—energy, digestion, bloating—to create personal accountability.
- Use the app to track dietary pattern changes monthly and correlate with self-reported symptoms like bloating, energy levels, and digestion quality. If possible, schedule quarterly blood work to measure cholesterol and inflammatory markers. Create a dashboard showing your “sulfur microbial diet score” trending downward over time, with visual rewards for maintaining improvements.
This research is observational and cannot prove that the sulfur microbial diet directly causes the health changes observed. The study was conducted in overweight and obese adults and may not apply to other populations. Individual responses to dietary changes vary significantly. Before making major dietary changes, especially if you have existing health conditions, high cholesterol, or take medications, consult with your healthcare provider or a registered dietitian. This article is for informational purposes and should not replace professional medical advice.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.