Ever wondered how your habits affect your gut health? Try our Gut Microbiome Score Calculator! It's fun and easy to use. You'll get a personalized score from 0 to 100 that shows what you're doing great and where you can improve. Plus, learn all about the gut microbiome and why it's so important for your health. Ready to boost your gut health? Let's dive in!
We try our best to make this tool as precise and reliable as possible. However, it can never replace a professional doctor's assessment. If any health condition bothers you, consult a physician.
Your Gut Microbiome — What Is It?
Picture a bustling metropolis of tiny, hardworking residents right inside you — that's your gut microbiome! A vibrant community of microbes that call your gut home 🏡. They might be small, but they are not to be underestimated: the number of bacterial cells residing in our gut even exceeds the number of our own cells. Although we often associate "bacteria" with illness, your gut bacteria are actually some of your greatest allies. They don't just keep things running smoothly in your digestive system; they're key players in overall health.
Think of your gut bacteria as a personal health squad. They help control your metabolism, determine how well you fight off infections, and even influence your risk of developing certain diseases, including cancer. Understanding the complex relationship between your gut and your health can be challenging, but we're here to break it down for you.
By getting to know your gut microbiome better and discovering how your daily habits shape your gut health with our easy-to-use calculator, you can make informed choices that promote a healthier, happier you. Let's delve in and discover how you can build a harmonious relationship with your gut bacteria 🤗!
How Your Gut Microbiome Affects Your Health
Are you curious why everyone is talking about the gut microbiome and its impact on our health? Wondering how it's linked to almost everything? Let's find out if these claims are solid or just hype.
Our gut isn't just for digestion — it's a massive part of our immune system, packed with most of our immune cells. It helps us fight infections and manage allergies. Ever heard the term "second brain"? That's our gut! It constantly communicates with our actual brain through the gut–brain axis, and gut microbes even help produce neurotransmitters such as dopamine and serotonin, which affect our mood and well-being.
Gut bacteria also:
- Digest fiber that we cannot break down ourselves and turn it into short-chain fatty acids (such as butyrate), the main fuel of the cells lining the colon;
- Protect the gut barrier, the thin layer that keeps food particles and microbes out of the bloodstream;
- Produce vitamins, including vitamin K and several B vitamins;
- Shape metabolism: they influence how much energy we extract from food, blood sugar control and fat storage;
- Crowd out pathogens by competing with harmful microbes for space and nutrients.
How Gut Imbalance Leads to Illness
When the balance of gut microbes is disturbed, scientists call it dysbiosis: fewer beneficial species, lower diversity and more room for microbes that promote inflammation. The protective gut lining can become more permeable, and inflammatory signals can spread throughout the body.
Dysbiosis has been linked with irritable bowel syndrome, inflammatory bowel disease (Crohn's disease and ulcerative colitis), Clostridioides difficile infection after antibiotics, obesity, type 2 diabetes, fatty liver disease, cardiovascular disease, allergies, colorectal cancer, and even depression and anxiety. In many of these conditions it is not yet clear what comes first, the disease or the imbalance, but a diverse and stable microbiome is consistently associated with better health.
What Shapes Our Gut Microbiome?
Your microbiome starts forming at birth. The way you were born (vaginal delivery or C-section), breastfeeding and early antibiotic use all leave a mark. Genetics, age and where you live matter too. But the good news is that daily habits have a large and fast effect: the gut microbiome can change within days of a change in diet.
The strongest modifiable factors are what you eat (especially fiber and the variety of plants), antibiotics and other medicines, alcohol, smoking, physical activity, sleep and stress. These are exactly the factors this calculator scores.
How to Use the Gut Microbiome Score Calculator
- Choose your measurement system. In the American system, you enter drinks in fluid ounces, weight in pounds and height in feet and inches; in the metric system, in litres, kilograms and centimetres. Switching the system converts the values you have already typed.
- Answer the diet questions: how many different plant foods you eat in a week, grams of fiber a day, servings of fermented foods and of red or processed meat a week, alcoholic drinks a week, how often you eat ultra-processed foods and sweets, and how much you drink a day.
- Answer the lifestyle questions: minutes of moderate or vigorous exercise a week, hours of sleep, stress level and smoking.
- Add your health history: courses of antibiotics in the last 12 months, your weight and height (used for the body mass index).
You get a score out of 100, the subtotals for diet (65 points), lifestyle (25 points) and health history (10 points), a list of what you are doing great, and a list of areas to improve, sorted by how many points each one costs you, with your current value and the target. Every step of the calculation is shown with your own numbers.
How the score is built
| Factor | Full points for | Max |
|---|---|---|
| Plant diversity | 30 or more different plants a week (proportional below) | 15 |
| Dietary fiber | 30 g a day or more (proportional below) | 15 |
| Fermented foods | 14 servings a week, about 2 a day (proportional below) | 10 |
| Ultra-processed foods | rarely (5), a few times a week (3), daily (1), most meals (0) | 5 |
| Sugary drinks and sweets | rarely (5), a few times a week (3), once a day (1), several times a day (0) | 5 |
| Red and processed meat | 3 servings a week or fewer; 0 points at 14 | 5 |
| Alcohol | 0–3 drinks a week (5), 4–7 (3), 8–14 (1), more (0) | 5 |
| Fluids | 2 L (67.6 fl oz) a day (proportional below) | 5 |
| Physical activity | 150 minutes a week (proportional below) | 10 |
| Sleep | 7–9 h (5), 6–7 or 9–10 h (3), 5–6 or 10–11 h (1) | 5 |
| Stress | low (5), moderate (3), high (1), very high (0) | 5 |
| Smoking | never (5), former (4), current (0) | 5 |
| Antibiotics in 12 months | none (5), one course (3), two (1), three or more (0) | 5 |
| BMI | 18.5–24.9 (5), 25–29.9 (3), under 18.5 (2), 30–34.9 (1), 35 or more (0) | 5 |
Scores of 80 and above are excellent, 60–79.9 good, 40–59.9 fair, and below 40 need attention.
Example. Alex eats 15 different plants a week (15 / 30 × 15 = 7.5 points), 18 g of fiber a day (18 / 30 × 15 = 9.0), 3 servings of fermented foods a week (3 / 14 × 10 = 2.1), ultra-processed foods a few times a week (3), something sweet once a day (1), 5 servings of red meat a week (5 × 9 / 11 = 4.1) and 4 drinks a week (3). Alex drinks 64 fl oz (1.89 L) a day (4.7), exercises 90 minutes a week (6.0), sleeps 7 hours (5), feels moderate stress (3), has never smoked (5), took one course of antibiotics last year (3) and, at 165 lb (74.8 kg) and 5 ft 8 in (1.727 m), has a BMI of 25.1 (3). The total is 59.4 out of 100: fair. The biggest gains are in fermented foods (7.9 points lost), plant diversity (7.5) and fiber (6.0); fixing just these three would bring Alex to 80.8, an excellent score.
What to Eat for a Healthy Gut
- Aim for 30 different plants a week. In the American Gut Project, people who ate 30 or more different plant types a week had a more diverse microbiome than those who ate 10 or fewer. Vegetables, fruit, whole grains, legumes, nuts, seeds, herbs and spices all count.
- Eat plenty of fiber, at least 25–30 g a day (most people eat about half of that). Legumes, whole grains, vegetables, fruit, nuts and seeds are the best sources. Fiber that feeds gut bacteria is called a prebiotic: onions, garlic, leeks, asparagus, bananas, oats and chicory root are especially rich in it.
- Add fermented foods daily. In a 2021 Stanford study, people who ate about six servings of fermented foods a day for 10 weeks increased their microbiome diversity and lowered markers of inflammation. Yogurt and kefir with live cultures, sauerkraut, kimchi, kombucha and miso are good choices.
- Include polyphenol-rich foods such as berries, cocoa, green tea, coffee, olive oil and colorful vegetables. Gut bacteria use polyphenols too.
- Limit ultra-processed foods, added sugar and red or processed meat. They are low in fiber, and some additives (emulsifiers, some sweeteners) disturb gut bacteria in studies.
- Drink enough fluid, about 2 L (67.6 fl oz) a day from drinks, more when it is hot or you are active, and increase fiber gradually to avoid bloating.
Beyond Diet — Other Factors
- Antibiotics save lives, but each course also reduces beneficial bacteria, and full recovery can take months. Use them only when a doctor prescribes them and always finish the course.
- Exercise is associated with more butyrate-producing bacteria, independently of diet. The WHO recommends at least 150 minutes of moderate activity a week.
- Sleep: gut microbes follow a daily rhythm. Short or irregular sleep and shift work disturb it.
- Stress travels along the gut–brain axis in both directions. Chronic stress changes gut motility, the gut barrier and the microbiome.
- Smoking and alcohol both damage the gut lining and change the microbiome; quitting smoking changes it within weeks.
- Body weight: obesity is linked with lower microbiome diversity, and so is being underweight.
- Pets, gardening and time in nature expose you to a wider variety of friendly microbes.
FAQs
Can this calculator test my gut bacteria?
No. It scores your habits, the factors that research links with a diverse and healthy microbiome. Only a laboratory stool analysis can show which microbes you actually have, and even those tests have limited value for everyday health decisions.
How fast can I change my gut microbiome?
Measurable changes appear within days of a change in diet. Lasting improvements in diversity usually take weeks to months of consistent habits.
Should I take probiotics?
Probiotic supplements help in some specific situations, such as preventing diarrhea during antibiotic treatment, but they are not needed by most healthy people. A varied, fiber-rich diet with fermented foods feeds the microbes you already have. Ask your doctor before taking supplements, especially if you have a weakened immune system.
What counts as a "different plant"?
Every distinct vegetable, fruit, whole grain, legume, nut, seed, herb or spice counts once a week. Red and green peppers count as one, as do an apple eaten on Monday and another on Friday. A handful of mixed seeds can add four or five plants at once.
Why does the calculator ask for my weight and height?
They give your body mass index (BMI), because both obesity and being underweight are associated with a less diverse microbiome. In the American system, the calculator converts pounds to kilograms and feet and inches to metres and shows every step.
What are the signs of an unhealthy gut?
Frequent bloating, gas, diarrhea, constipation, heartburn, unintended weight changes or fatigue may point to a gut problem. Blood in the stool, unexplained weight loss or persistent pain need a doctor's visit.