The Flatulence Fighting Toolkit (No More Excessive Wind)

What Is Normal vs Excessive Flatulence?

Gas production and flatulence is completely normal and even beneficial. To some extent, intestinal gas aids in digestion by softening and helping to move waste through our intestines.1 

Daily gas expulsion averages 600–700 mL/day.2

On average, people experience flatulence 14 to 25 times per day.2 

Of course, if you're finding yourself passing wind at a much higher rate - or noticing it is particularly smelly - then you might be experiencing excessive gas.

What Causes Flatulence?

1. Production by our gut microbes, a.k.a. microbial fermentation (food related) 3,4
2. Swallowed air 3,4 
3. Gases in our blood that crossover into the gut (e.g. carbon dioxide)3,4
4. Gases released when our stomach acid mixes with alkaline secretions from foods 3  This produces carbon dioxide which may be belched or absorbed into the blood and exhaled by the lungs.4  Kind of like the vinegar, baking soda, and balloon science project you may have tried when you were a kid

Out of the four causes of gas, the two biggest contributing factors to flatulence are swallowed air and gut microbe fermentation.5

Microbial Fermentation

• The remaining gases are mostly produced by microbes in our guts and include gases such as hydrogen, methane, and carbon dioxide. These gases make up the vast majority of expelled flatus; around 74%.6
• Our gut microbes produce gas by breaking down food particles that escape our digestive enzymes and make it down to our lower gut and colon.2 
• You may have noticed certain foods make you gassier, and a lot of that has to do with how much of a given food your body is unable to digest and absorb. For instance, 20% of carbohydrates in baked beans, 7–10% in wheat, oats, potatoes, and corn, and 1% in white rice aren’t absorbed by us.2 
• These indigestible parts of foods, particularly certain carbohydrates such as fiber, prebiotics, resistant starches, or sometimes sugars such as lactose, sorbitol, or fructose, travel down to our lower guts for microbial fermentation resulting in an increase in gas production.2
• For a full list of foods that can cause flatulence see just below in this post.

Swallowed Air

• The nitrogen and oxygen found in intestinal gas comes primarily from swallowed air.8 
• We may be able to limit the amount of air we swallow to a certain degree by not eating too quickly, avoiding smoking, not chewing gum, avoiding drinking from a straw, and opting for non-carbonated beverages.3,5 
• However, some swallowed air is unavoidable. We swallow air when eating food; for instance roughly 20% of an apple is made up of gases by total volume, and drinking a glass of water can lead to twice as much air consumption as water. 9 
• Some of this gas is expelled by belching, though some may also pass into the stomach and our lower intestines.9
• When not expelled through belching, swallowed oxygen is typically absorbed throughout the intestinal tract into the bloodstream, and is mostly absent in the lower gut.8 
• On the other hand, nitrogen is not absorbed, so when nitrogen passes through the stomach and into the lower gut, it is evacuated rectally as flatus.8 Fortunately, nitrogen is not an odor-contributing gas.4  

13 Common Foods That Cause Flatulence

1. beans
2. lentils
3. cabbage
4. broccoli
5. cauliflower
6. bok choy
7. Brussels sprouts
8. bran
9. dairy products containing lactose, such as milk or cheese
10. fructose, found in some fruits and often used as a sweetener in soft drinks and candy
11. sorbitol, a sugar substitute found in candies and artificial sweeteners
12. carbonated beverages, such as soda and beer
13. wheat

• Lactose - People of ethnic origins other than Northern and Western European commonly have an impaired ability to break down lactose. If you are not of Northern or Western European descent and are experiencing excessive flatulence after dairy consumption, lactose intolerance should be highly suspected. Of note, even in the setting of lactose intolerance, it is not uncommon for individuals to tolerate some forms of fermented dairy such as yogurt.4  Likewise, even when lactose intolerance is present, people with lactose intolerance can often tolerate up to 12 g of lactose, or 250 mL of milk with minimal to no symptoms, or possibly even more when consumed with other foods.24 MORE INFO? Work with a medical professional for guidance on how to manage lactose intolerance and to determine what your individual tolerance might be regarding dairy products and foods such as yogurt. 
• Sorbitol - this is a natural substance in fruits and is used as an artificial sweetener. This sugar is malabsorbed by 43% of caucasian individuals, and 55% of non-caucasians at doses as low as 5 grams.2 Other potentially malabsorbed carbohydrates include isomalt, xylitol, and rarely, sucrose (table sugar).2 If you’re experiencing excessive flatulence, be particularly mindful of these dietary components, especially suspecting sugar free food products containing sugar alcohols as a potential cause. To spot sugar alcohols on food labels, the names typically end in ‘tol’ (e.g. sorbitol, xylitol, erythritol, etc.) 
• Fructose - interestingly fructose malabsorption may be another underlying factor to explore, as malabsorption of this sugar leads to water being drawn into the intestines, often resulting in diarrhea and excessive flatulence. Certain fruits and dried fruits, fruit juices, high fructose corn syrup, table sugar, honey, and agave syrup in the diet can exacerbate GI symptoms from fructose malabsorption. 25  If you suspect fructose malabsorption may be at the root of your flatulence issues, it is important that you work with a medical professional such as a registered dietitian to identify which foods may be producing symptoms. 

What Causes Smelly Flatulence?

Over 99% of intestinal gases are odorless and made up of nitrogen (N2), oxygen (O2), carbon dioxide (CO2), hydrogen (H2),and methane (CH4).4,6 The remainder is made up of trace gases such as nitric oxide (NO) and odor producing sulfur compounds such as hydrogen sulfide, methanethiol, dimethyl disulfide, and dimethyl trisulfide.4,6 

Sulfur-containing compounds are responsible for that distinct ‘rotten egg’ smell of flatulence.7 

Side note: In the name of science, some individuals really took one for the team when it came to determining exactly which parts of farts stink:

Image Reference: 7

Thanks to these efforts, we now know that hydrogen sulfide is the intestinal gas which most significantly contributes to the odor of flatus.7

When Is Flatulence A Big Problem?

Obviously, if you find it gets in the way of living your life freely, it is a problem worth fixing.  So if you find it embarrassing, or something you're always mindful or even anxious about, it deserves a solution.

But there are also other times when it may need serious attention.

Uncomfortable symptoms

Indeed, flatulence can quickly turn from being a normal and healthy bodily process to impacting our quality of life. Usually flatulence can become problematic under the following circumstances:2,21,22

• Abnormal perception of excessive gas production
• Excessive gas production related to an underlying medical condition
• Hypersensitivity or pain from normal amounts of gas in our intestines 
• Bloating 
• Gas that has an offensive odor 
• Loud bowel sounds when digesting and/or defecating

Underlying medical issues

It can even become a medical concern, when it signals an underlying medical issue.

If you have any of the following warning signs in addition to flatulence, it’s imperative you seek medical attention to rule out a more serious underlying cause or diagnosis.2 In the case of a medical diagnosis, it’s important to follow the diet, lifestyle, and medication guidance offered to you by a healthcare professional.

• Nausea or vomiting
• Fever
• Weight loss
• Muscle pain or weakness
• Fatty or greasy looking stools
• Rectal bleeding 
• Skin or hair changes
• Palpable masses 
• Presence of abdominal pain 
• Abnormal abdominal distention 
• Diarrhea 
• Sudden change in bowel habits
• A family history of colon cancer, inflammatory bowel disease, or celiac disease
• Feelings of incomplete evacuation 
• Frequent straining, abdominal pressure, or the need for digital manipulation or manual disimpaction when having a bowel movement
  

Medical issues associated with flatulence

• Lactose intolerance or carbohydrate malabsorption 
• IBS
• Crohn’s Disease
• Eating Disorders
• Ulcerative Colitis 
• Dumping Syndrome 
• GERD
• Autoimmune pancreatitis or pancreatic insufficiency
• Peptic Ulcers 
• Celiac disease
• Impaired Gas Evacuation; pelvic floor abnormality or malfunction
• Gluten intolerance
• Constipation 
• Abnormal abdominal wall reflex
• Bacterial overgrowth; SIBO 
• Colon cancer
• Gastroenteritis
• Gastroparesis
• Medications - including but not limited to, Anticholinergics, opiates, calcium blockers, antidepressants, antibiotics2.  Some medications may also produce gas by altering gut motility2

Ways To Reduce Flatulence (Short-Term)

This information is only suitable for those who do not have an underlying medical diagnosis stimulating their flatulence problem. Anyone with an underlying disease process should follow medical guidance.

Treatments and Solutions for Flatulence:21,38,49      

Cut Down Troublesome Foods

• Chances are, if you’re in the 15-20% of individuals in the US complaining of a flatulence problem, you’ve likely already done your research, and crossed off beans, cabbage, and all possible flatulence-inducing items on your grocery list.10
• Following conventional diet recommendations that restrict fibrous and gas forming foods will lower the amount of gas you have over the short term. One study found that a fiber-free diet reduced the daily average amount of expelled gas from around 700 mL down to just 200 mL.2 
• With that, going easy on the beans, fiber, and poorly absorbed carbohydrates might be a useful tactic before a first date or job interview, but the reality is that many of these foods are some of the most beneficial for us, and eliminating them entirely may not be in our best interests.
• While fermentation of fibers and other carbohydrates leads to more gas production, there are other really beneficial compounds made in this process as well. For instance, fiber and prebiotic fermentation can lead to the production of compounds called short chain fatty acids (SCFAs). Benefits of SCFAs happen in the gut and for the whole body. SCFAs may help to:
• Improve immune health and inflammation11
• Aid colon cancer prevention11,12         
• Regulate blood sugars13          
• Improve cardiovascular health14,15 
• Improve appetite regulation and satiety16 
• Prevent pathogenic microbes from wreaking havoc in our guts (e.g. E. coli, salmonella, etc.)17 
• Contribute to psychological benefits and protection of brain functioning18      (source)   
• In the absence of a gut-related medical diagnosis, intestinal disruptions such as flatulence, bloating, and abdominal discomfort after eating fibrous or gas forming foods, often only occurs when these foods are eaten in excess, or when there isn’t appropriate acclimatization -- a gradual build up towards higher fermentable fiber intakes.19 
• There’s also evidence that gradually increasing fiber intakes over time, while not getting rid of gas production, may help us to have better tolerance of the gas we do produce.19 
• It is also important to consider that some individuals who report problems with excessive flatulence have gas expulsion levels that are in normal, healthy ranges. In this case, these individuals often experience poor tolerance of normal gas levels.9  This may be improved through education of the body, decreasing stigma around normal bodily processes, and encouraging the individual to slowly and consistently increase fiber in their diet.
• Rather than trying to get rid of a normal bodily process, we may be better off to work towards better tolerance of the gases we will inevitably produce, while following a balanced and healthy diet. 

Important side note: Flatulence related to lactose intolerance is likely to not improve with continued exposure. Lactose intolerance is due to enzyme deficiencies in the gut which can be managed, but not reversed. Some studies have demonstrated that certain prebiotics such as galactooligosaccharides (GOS) might improve lactose tolerance by increasing lactose fermenting microbes in the gut.20 If you’re seeking to improve lactose tolerance with targeted gut therapies, it’s advisable to work with a specialist.

• Source: enzyme derived from Aspergillus niger mold27 
• Action: Breaks down non-absorbable carbohydrates called oligosaccharides before they are metabolized by colonic bacteria to prevent overproduction of gas.27 
• Foods which contain oligosaccharides in which, upon consumption, Beano might be effective for preventing excessive flatulence:28 
• Cereals: Rice, Bran, Spelt, Maize, Oats, Barley, Muesli
• Pulses: Beans, Chickpeas, Broad Beans, Lentils, Peas, Soy
• Fruit: Oranges, Bananas, Kiwi, Grapefruit 
• Nuts: Peanuts, Almonds, Hazel nuts, Walnuts, Pistachios, Pine nuts
• Vegetables: Asparagus, Broccoli, Carrots, Cabbages, Cucumbers, Onions, Mushrooms, Potato, Leeks, Peppers 
• Effective Dosing: 
• 300-1200 GalU in the setting of eating 420 grams of cooked beans has been found to be effective in lowering gas production. The higher dose of 1200 GalU was most effective.28 
• 2 tablets of Beano = 800 GalU dose
• Must be taken with gas-producing foods/meals to be effective; follow packaging instructions for administration 
• Potential side effects:
• As Beano is derived from a food-grade mold; if you are allergic to mold, you may have a reaction to Beano.29 
• Individuals with a rare disorder called galactosemia (an inherited disorder in which you are unable to metabolize galactose) should not use Beano without first speaking with a physician.29 
• Beano works by lessening microbe fermentation in the gut. This could potentially have downstream effects on our microbiome, though no current studies have looked into this possibility.
  

Simethicone (e.g. Gas-X)

• Source: Composed of silicon-based structures and silica gel30
• Action: Antifoaming agent thats acts in the gut to reduce the surface tension of gas bubbles; it is not absorbed into the bloodstream30
• Effectiveness: While promoted as a treatment for gaseousness, the effectiveness for simethicone for flatulence is not convincing.31 That said, Simethicone does appear to be more effective than a placebo treatment for relieving diarrhea and abdominal discomfort.32 Simethicone may also be helpful for post-surgical abdominal discomfort in infants, and for functional dyspepsia.32 
• Dosing: (adults)33
• Tablets: 200 mg-simethicone 25 mg: 2 to 4 tablets orally up to every hour as needed for symptoms, or as directed
• Maximum dose: 12 tablets/day
• Liquid/Oral suspensions: 400 mg-simethicone 40 mg/10 mL: 10 to 20 mL orally 4 times a day or as directed
• Maximum dose: 80 mL/day
• Liquid/Oral suspensions: 800 mg-simethicone 80 mg/10 mL: 10 to 20 mL orally between meals, at bedtime, or as directed
• Maximum dose: 60 mL/day

• Potential Side Effects: 

• Constipation or Diarrhea (uncommon; 0.1-1%)
• Hypermagnesemia (very rare; less than 0.01%) 

• Action: Works to lower hydrogen sulfide levels in flatulence and feces; a potentially inflammatory compound and the primary odor causing constituent of flatus.34 This medication is used to treat diarrhea, nausea, heartburn, indigestion, gas, or upset stomach. 
• Effective Dosing: (Adults)35 
• 524 mg orally every 30 to 60 minutes as needed not to exceed 8 doses in any 24 hour period.
• Alternatively, 1048 mg to 1050 mg may be given orally every hour not to exceed 4 doses in any 24 hour period.
• Do not use longer than 2 days without medical guidance

• Potential Side Effects: 

• Do not take this medication if you have black or bloody stools, a stomach ulcer, bleeding problems, or if you’re allergic to salicylates such as aspirin.36 
• Long term use of Bismuth compounds is associated with neurotoxicity.34 If you experience any atypical symptoms while taking pepto-bismol such as increased thirst, sweating, altered mental or emotional state, pain, uncontrollable movements, weakness, or spasms, immediately discontinue use and seek medical care.37 

• Activated Charcoal

• Has been found to be ineffective when taken orally at doses of 0.52g, 4 times per day for one week at decreasing the odor of feces or flatus.38 
• External devices such as activated charcoal lined underwear, pads, and seat cushions have shown some effectiveness in reducing flatus odor. Activated charcoal underwear were shown to be the most effective, pads were moderately effective, and seat cushions having been shown to be minimally effective.21 
• 
  

  Zinc acetate

• (demonstrated in animal model studies) 

• In rats, adding zinc acetate to food decreased fecal hydrogen sulfide concentrations and improved flatus odor. Another study found that an oral treat containing zinc acetate, activated charcoal, and yucca schidigera extract reduced “highly odoriferous episodes” of flatus in dogs.39

• • If taking oral zinc acetate, please speak with a healthcare provider first to ensure this is appropriate for your individual medical needs 
  • Prolonged high dose zinc supplementation may result in copper deficiencies. The tolerable upper limit for individuals aged 19 or older is 40 mg/day, including both dietary and supplemental zinc intakes.40 Total daily zinc intakes should not exceed this level in the absence of medical guidance. 
  • Zinc may also cause side effects when given in high doses such as nausea, vomiting, loss of appetite, abdominal cramps, diarrhea, and headaches.40

  Natural Carminatives:

  Fewer studies are available on natural gas relieving substances (carminatives) such as spices and herbs. However, plant and herbal preparations have been used for gastrointestinal woes throughout human history. Below are some suggested natural carminatives that can easily be added into the diet in normal culinary doses (e.g. adding spices to foods, herbal teas, etc.)

  If you intend to take any natural herbal supplements or spices in doses that exceed culinary doses, please discuss doing so with a healthcare provider first to avoid potential negative side effects, toxicity, or drug interactions. 

  Exercise:

• Exercise may be helpful in relieving abdominal bloating and discomfort from gas. One study performed on individuals with IBS or complaints of bloating found that significantly more gas was retained at rest, while mild physical activity enhanced gas clearance and reduced symptoms of bloating.47

  Probiotics:

  The evidence for using probiotics to help with flatulence is mixed and sometimes hard to decipher. Each probiotic has a unique blend of microbial strains, meaning that broadly classifying probiotics as effective or ineffective for flatulence doesn’t offer a clear picture; it’s important to look at individual strains and precise probiotic blends. Most studies evaluating the use of probiotics for flatulence have been performed in individuals with IBS, so results may or may not be able to be extrapolated onto people without IBS. Overall the quality of evidence to support the use of probiotics for flatulence remains low, though some studies and probiotic blends have been used successfully to reduce flatulence: 

• VSL #3
• VSL#3 is a high-concentration probiotic available by prescription consisting of four strains of lactobacilli (Lactobacillus casei, L. plantarum, L. acidophilus and L. delbrueckii subsp. bulgaricus), three strains of bifidobacteria (Bifidobacterium longum, B. breve and B. infantis) and Streptococcus salivarius subsp. thermophilus.48
• VSL#3 demonstrated a 50 percent reduction in flatulence in more patients at four weeks compared with placebo (52 versus 33 percent)21
  
• Lactobacillus plantarum 
• Lactobacillus plantarum provided in 400 ml of a rose-hip beverage( 5x10 (7) cfu/ml per day) decreased pain and flatulence in individuals with IBS.49 
• Prescript-Assist
• Prescript-Assist is a 28 strain soil based probiotic which also contains prebiotics. Treatment with this probiotic-prebiotic complex may be an option for short-term (2–4 weeks) and long-term (60-week) reductions in IBS symptoms including flatulence.50 
• Constituents of Prescript-Assist: Leonardite, Arthobacter globiformis, Azospirillum brasilense, A.lipoferum, Azotobacter chrooccum, A.paspali, A.vinelandii, Bacillus amyloliquefaciens, B.atrophaeus, B.licheniformis, B.megaterium, B.pumilus, B.subtilis, B.thuringiensis, Bacillus firmus, Brevibacillus brevis, Cellomonas fimi, Kurthia zopfii, Micrococcus luteus, Nocardiodes simplex, Pseudomonas fluorescens, P.putida, Rhodoacter sphaeroides, Rhodococcus rhodochrous, Rhodopseudomonas palustris, Streptomyces griseus, Streptomyces griseoflavus, Streptomyces venezuelae.Other Ingredients: Cellulose (vegetarian capsule) L-leucine, Bamboo (Bambusa vugaris) extract.)51

The Smart Way To Reduce Flatulence (Long-Term)

• Sadly, diet strategies that reduce fiber and fermentable carbohydrates in the short term  (when not recommended or undertaken with medical guidance) may not be addressing imbalances in our microbiome that could lead to chronic issues with flatulence. In fact, there are ways a long term low fiber diet might even worsen a chronic flatulence problem. 

• While commonly people who complain of excessive flatulence still have gas expulsion amounts in the ‘normal’ range and similar to those of people without flatulence complaints, certain microbes in the gut have been associated with a higher gas output.52 
• One microbe in particular that’s associated with this is called Bilophila wadsworthia.52 This microbe is one of many microbes that can use hydrogen produced from fermentation of undigested fibers, carbohydrates, and proteins in the large intestine to create hydrogen sulfide. 
• When in balance, hydrogen sulfide can be a beneficial compound in the body, helping injuries in the gut to heal, or possibly even improving inflammation.53 
• When hydrogen sulfide levels are too high in the gut, the opposite effect may happen.53 Hydrogen sulfide producing microbes have been found in excess in people with inflammatory conditions such as IBD, Crohn’s Disease, and colorectal cancer.53,54  
• You may also recall that hydrogen sulfide is the odor forming part of flatus giving it that distinct, rotten egg, sulfur smell.7 
• While intuitively, you might think that restricting fiber and carbohydrate fermentation in the gut is the best way to keep this microbe and other hydrogen sulfide producing microbes in check, the opposite may be true. Of all dietary factors which promote the abundance of Bilophila wadsworthia and other hydrogen sulfide producing microbes in the gut, excess animal protein and certain dietary fats may be primary factors.55  Additionally, hydrogen sulfide is produced when sulfur containing amino acids, which make up protein, such as cysteine, methionine, cystine, and taurine are consumed and fermented in the gut.   56
• Likewise, high intakes of saturated fat (particularly dairy fat) also promotes blooms of Bilophila wadsworthia, while the same microbe may actually be inhibited by unsaturated fats such as fish oil.56 
• It is also true that sulfur compounds contained in garlic, onions, cruciferous vegetables (e.g., cabbage, cauliflower, kale, broccoli, etc.), and durian fruit can directly release hydrogen sulfide..  54 
• However, one study actually found that cruciferous vegetables may even lower overall numbers of hydrogen sulfide producing bacteria in the gut.57 
• Even more, core gut microbes distinct from hydrogen sulfide producing bacteria appear to use sulfur-containing compounds called glucosinolates; compounds which are found in cruciferous vegetables.58 These microbes transform glucosinolates into isothiocyanates. The production of isothiocyanates is associated with cancer preventive properties.58
• Likewise, in one study, a twice daily garlic-derived sulfur compound was given to dogs in high doses for 5 days. Supplementing with a garlic-derived sulfur compound, while increasing hydrogen sulfide production, produced no detectable damage to the gastrointestinal lining, as well as no inflammation. 54
• It has been found that individuals who experience uncomfortable amounts of flatulence often have higher numbers of inflammatory microbes categorized under the Bacteroides fragilis group.52 Researchers believe that these inflammatory microbes, that are common to people struggling with uncomfortable or excessive flatulence, may cause inflammation and pain in the gut, which could even lead to hypersensitivity of normal volumes of gas in the intestines.52 Interestingly, Bacteroides fragilis has been shown to be stimulated by a high fat and low fiber diet, while the reverse of a high fiber and lower fat diet correlates with decreasing levels of this bacterial group.54 
• Even more, people with complaints of flatulence have also been found to have unstable microbiota which have very profound shifts in their microbial balance when challenged with a ‘flatulogenic diet.’52 When it comes to microbiome stability, one overarching pattern has been consistent: a microbiome with more microbes coming from the broad bacterial genus called Prevotella is more stable and less likely to undergo extreme fluctuations which could possibly bring about gut symptoms.59
• Prevotella dominance is associated with a long term high fiber and plant rich diet, suggesting that adopting this type of diet pattern as a lifestyle could potentially help to stabilize the gut ecosystem, and possibly also gut symptoms such as flatulence.60

Our Summary

Reducing fiber and gas forming foods may be helpful in the short term, but theoretically could be a setup for continued flatulence problems and discomfort over the long term.

While more studies are needed, the key to resolving discomfort and excessive odors associated with flatulence may be to gradually increase beneficial flatulogenic foods; slowly building tolerance and improving the microbiome composition, while minimizing the risks of side effects.