Bitters can help to improve digestion, relieve gut inflammation & protect against stomach ulcers. In this post, we discuss the top 9 herbal bitters and the studies showing benefits for them.
9 Best Herbal Bitters
The Gentian family includes over 400 species, all of which are commonly referred to as Gentian and have a strikingly long history of use. Gentian got its name from King Gentius who ruled in the Mediterranean region in 181 BC. Modern Gentian is native to Europe, parts of Iran, and Tibet [1+].
Gentian can help with digestion by promoting saliva and stomach acid production, as well as by increasing blood flow to the stomach and intestines [2+].
In one study, 4 different species of gentian herbs all promoted digestion in rats. They increased stomach acid and the digestive enzyme pepsin. Gentian could also boost mucus levels, which helps prevent damage from stomach acid [3+].
In rats with impaired gut flow, the active compound from gentian (gentiopicroside) restored normal digestion .
Gentian extracts can protect against stomach ulcers and alcohol damage to the stomach lining, according to numerous animal studies. And as an additional benefit, Gentian extracts have antibacterial and antifungal effects [5, 6, 7, 8].
2) Citruses (Bitter Orange)
Citruses are flowering trees that include lemons, limes, oranges, and others. All citruses originate from southeast Asia but only some have bitter qualities. The main bitter from this group is bitter orange (Citrus aurantium) [9+].
In rats with IBS, bitter orange reduced diarrhea, colon inflammation, and inflammatory molecules (TNF-alpha, COX-2). A bioactive molecule from bitter orange essential oil (Β-myrcene) reduced stomach and intestinal ulcers in rats [10, 11].
Bitter orange peel essential oil decreased stomach ulcer size and helped grow new blood vessels to aid in the healing process in rats. In another rat study, this essential oil protects against stomach injuries caused by alcohol or anti-inflammatory drugs (NSAIDs) by increasing stomach mucus levels in rats [12, 13].
A flavonoid found in citrus peels (Nobiletin) improved gut barrier integrity and had anti-inflammatory healing effects in rats with colon inflammation. It may help people with leaky gut. However, other flavonoids can actually worsen leaky gut. Some of the ones in bitter orange (Hesperidin and neohesperidin) worsened ulcers and intestinal permeability in rats [14, 15].
Although clinical trials haven’t been conducted, animal studies support the benefits of dandelion for digestion. In pigs, it improved food digestion and reduced E. coli in the gut. In rats, it helped move food from the stomach to the gut [21, 22].
In fish, dandelion extracts boosted intestinal immunity and antioxidant activity. They also improved gut “shape”, which may aid in better digestion and nutrient absorption .
Dandelion also has anti-inflammatory properties. In rats, dandelion improved both short-term and long-term stomach inflammation (by blocking mast cells entry into the stomach and decreasing TNF-alpha) .
In mice and cell-based studies, dandelion extracts prevented colon inflammation (reducing COX-2, IL-1Beta, and TNF-alpha) and promoted the growth of 14 different strains of beneficial probiotic bacteria (bifidobacteria) [25, 26, 27, 28].
Burdock (Arctium lappa) is a bitter and anti-inflammatory that has been used in North American, Asian, and European folk medicine .
Multiple animal studies confirmed that burdock and its active components can protect against or speed up the healing of stomach injuries and ulcers. One of its active compounds (arctigenin) lowered colon inflammation in rats [30, 31, 32, 33, 34, 35, 36, 37].
Fermented burdock increased levels of the probiotic gut bacteria (bifidobacteria) in rats, unlike non-fermented burdock .
Inulin extracted from burdock enhanced the growth of beneficial bacteria. Inulin significantly increased good gut bacteria in mice and cells (lactobacilli and bifidobacteria). In one mouse study, burdock could also safely prevent weight gain [39, 40].
In a study of 208 people with IBS, artichoke leaf extract reduced constipation and diarrhea while improving the quality of life. By the end of the study, 26% of the participants no longer had IBS .
In a survey of people with indigestion and IBS, 96% said that artichoke was as good or better than previous treatments. It can help with IBS by preventing muscle spasms and balancing the gut microbiota [44, 45+].
Cynarin, a compound in artichoke extracts, increases bile production from the liver which aids in the digestion of fats and the absorption of fat-soluble vitamins (like vitamin A and D) .
Artichoke extracts prevent gut spasms in guinea pig intestines, which may relieve stomach pain. In rats, artichoke leaf extracts prevented damage to the stomach lining caused by alcohol or stress [47, 48].
Chamomile (Matricaria chamomilla) is a gentle plant with great medicinal value for which it is appreciated across the globe. In a clinical trial with 65 women undergoing chemotherapy for breast cancer, chamomile pills reduced vomiting frequency .
More clinical trials are lacking but animal studies support a variety of gut benefits. In guinea pigs, it decreased small intestine muscle spasms. In rats, it protected against ulcers and oxidative stress in the gut and reduced diarrhea. In rat colons, chamomile extracts lowered inflammatory molecules (such as IL-6, NF-KB, and TNF-alpha) [50+, 51, 52, 53, 54, 55].
7) Milk Thistle
Milk thistle (Silymarin) is best known as a liver support remedy and anti-inflammatory, but it also has bitter qualities that can enhance digestion.
Silymarin prevented ulcerative colitis from coming back in a clinical trial with 80 people .
Multiple rat studies show that it protects against stomach ulcers and inflammation (potentially by decreasing neutrophils and stomach acid). It may improve bile flow, which helps with digestion and the absorption of fats and fat-soluble vitamins [57, 58, 59, 60].
Goldenseal (Hydrastis canadensis), native to North America, is an herb that has been traditionally used to fight infections. Much of modern research has switched to berberine, a bitter compound found in Goldenseal roots with many medicinal qualities .
Berberin is a natural, safe anti-diarrheal. In a clinical trial with 196 people with irritable bowel syndrome (IBS), berberine significantly reduced diarrhea frequency and stomach pain, improving the quality of life. In another clinical trial with 165 people, berberine stopped diarrhea due to E. coli in 42% of the cases after just 1 day of use [62, 63].
In rats, berberine reduced gut inflammation (possibly by reducing lipid peroxidation and NF-κB levels). In diabetic rats, it helped restore the gut barrier and improved nutrient absorption [66, 67, 68, 69, 70, 71].
Berberine might be helpful for clearing toxins that reach the blood in people with leaky gut, such as LPS. In mice with high LPS (endotoxemia), it helped prevent leaky gut. In a gut tissue study, it blocked about 70% of the toxins produced by gut bacteria (Vibrio cholerae and E. coli) [72, 73].
Angelica is a plant genus with over 60 medical species (including Angelica gigas and Angelica sinensis), traditionally used to fight arthritis, indigestion, headaches, the flu, infections, and more. Dong Quai or “female ginseng” is one commonly used medicinal plant from this family .
Injections of Dong Quai (Angelica sinensis) helped improve ulcerative colitis in a study with 94 people (by preventing platelet activation) .
In a rat study, extracts of Dong Quai greatly reduced the size of stomach ulcers and increased the production of protective mucus production. In another study, extracts protected rats from ulcers and stomach damage [79, 80].
Synergistic Combinations of Herbal Bitters
Often times, bitter herbs are combined into mixtures that have synergistic effects.
Iberogast is a well-known product that contains 9 herbs:
- Bitter candytuft
- Lemon balm
- St. Mary’s thistle
- Greater celandine
It used for various gut issues, of which indigestion is the most important one. In an analysis of 6 clinical trials, Iberogast was effective at improving indigestion .
Iberogast also significantly decreased irritable bowel syndrome and relieved stomach pain in a clinical trial with 208 patients .
The Xiaoyao pill is traditional Chinese medicine that contains Dong Quai and other components. In a clinical trial of 180 depressed women with indigestion (functional dyspepsia), the Xiaoyao pill improved digestion by helping to move the food swiftly through the gut. It also raised motilin and gastrin levels, hormones that increase digestive proteins and stomach acid .
A combination of angelica, burdock, gromwell, and sesame eased inflammation and healed ulcers in a clinical trial of 36 patients with Helicobacter pylori .
In a clinical trial with 96 patients, a combination of chamomile, myrrh, and coffee charcoal prevented ulcerative colitis from coming back at the same rate as the standard drug treatment. It was also effective at reducing diarrhea, nausea, vomiting, pain, gas in a study of over 1k people [91, 92+].
One study examined the effects of Prodigest, a combination supplement with ginger and artichoke, in healthy people. Prodigest improved gut flow without side effects, helping to prevent vomiting, nausea, stomach pain, and bloating that can result from slow digestion [95, 96].
Cinarepa, an herbal mixture with dandelion, reduced indigestion in a study of 311 people .
In another study of 24 people, a mix with dandelion, St. John’s wort, lemon balm, and a couple of other herbs decreased stomach pain in over 95% of people with colon inflammation after about 2 weeks .
Bitter Orange Mixtures
An analysis of 22 clinical trials and almost 2,000 patients found that Modified Chaihu Shugan powder, a Chinese herbal combination that contains bitter orange, can be safely used to relieve indigestion .