While all forms of prebiotic fiber play a role in gastrointestinal health, pectin stands out as among the most important. While pectin is traditionally used to thicken jams, jellies, yogurts and other foods, it can also serve as a prebiotic fiber, given its polysaccharide structure. The sugar residues that characterize pectin (fibers are polymers, or chains, of sugars) differ from those in inulin/FOS and galactooligosaccharides from legumes, comprised instead of a mix of galactouronans, rhamnogalactouronans, galactose, rhabinose and others.
Increased intake of pectin fiber has been demonstrated to:
- Shift bowel flora composition towards enrichment in healthy Clostridia, Lactobacillus, and Bifidobacteria species, increasing the Bacteroidetes/Firmicutes ratio. (Despite the potent pathogenic potential of some Clostridia species, emerging evidence also suggests that other non-pathogenic Clostridia species may play important roles, for instance, in protecting from autism and other disorders.)
- Decreased pathogen populations—reduction in Clostridium perfringens and Clostridium difficile, Enterobacteriaceae (dominant in SIBO) and Pseudomonas
- Enhance survival of probiotic species in the upper gastrointestinal (GI) tract—a feature that may be especially helpful to upper GI-colonizers such as L. reuteri and L. gasseri.
- Increase production of short-chain fatty acids that nourish the intestinal lining and mediate numerous health benefits such as reduced insulin resistance and blood levels of triglycerides.
- Strengthen the intestinal mucus barrier and increasing intestinal immune response.
- Supports the important keystone species Faecalibacterium prausnitzii, the main butyrate producer of the human microbiome (that thereby yields many metabolic benefits).
Fruit is the primary source for pectin fiber. Among the richest sources of dietary pectin are (grams pectin per 100 grams fruit):
- Apples: 0.8 g
- Avocados: 2.4 g
- Blackberries: 1.4 g
- Blueberries: 0.8 g
- Raspberries: 1.6 g
- Pomegranate arils: 2.0 g
- Pears: 1.0 g
You can see that, while apples stand out in the public’s awareness of health effects, much of it mediated via pectin content, there are other fruits that have more pectin and thereby potentially greater effects on bowel flora, intestinal and overall health. Avocados, raspberries, blackberries, and pomegranates, in particular, are especially abundant sources. Other sources include carrots and citrus peels (e.g., orange or lemon zest).
You can also purchase pectin powders, though most come with sugars or are limited by high-cost for small quantities. Pomona’s Universal Pectin brand, for instance, costs around $5 for a 1.1-ounce/31-gram package. A 1/2-teaspoon serving therefore provides around 3 grams pectin that can be added to various foods; one package therefore yields around 10 servings. (We are adding pectin for prebiotic fiber purposes, not for jelling of jams and jellies.) If you have access to large quantities of apples, apple peels, or citrus peels, you can also make your own pectin.
Of course, we remain mindful of net carb exposure, as too much fructose, glucose, and sucrose from fruit also has health consequences. As with other prebiotic fibers such as inulin or legumes, the key is to include a prebiotic source, such as those containing pectin, in every meal in modest quantities, e.g., blueberries with L. reuteri yogurt, a small apple with your lunch, an avocado topped with salsa or pico de gallo. If you find yourself intolerant to pectin, this is a sign of dysbiosis, especially small intestinal bacterial overgrowth, SIBO, that is now prevalent at epidemic levels in the U.S. You should then consider taking specific action for SIBO.
Another interesting effect of pectin is that it has the unique capacity to bind heavy metals like lead, mercury, and cadmium that, once bound, are excreted in the urine. While not as potent as conventional chelating agents in the amounts we are discussing for prebiotic fiber augmentation, pectin can be a wonderful addition to prevent or minimize heavy metal toxicity.