Pectin: a versatile fiber source
Lark L. Burnham, Ph.D.
Pectin, which is derived
from apples and citrus fruit, is a highly soluble fiber. In general, different
fiber sources are classified by their ability to absorb water. They range from
basically insoluble (high lignin fibers such as seed hulls) to very soluble
(pectin and other gel-forming fibers). Solubility is important because it
determines how well the fiber will be digested by the gastrointestinal tract (GIT)
All mammals lack the
enzymes necessary to digest fiber. They depend on a synergistic relationship
with microorganisms to degrade it for them. The by-products of microbial
fermentation of fiber are short-chain fatty acids, primarily acetic, propionic,
and butyric acids.
water for viability and for fermentation. Greater water absorption by a fiber
means more extensive bacterial degradation or digestibility . Fibers that have
a very low solubility have digestibilities as low as 3%, while highly soluble
fibers are closer to 60% digestible. Wheat bran is intermediate, with a
digestibility of around 20%
ferment fiber are usually either beneficial or at worst, benign. Dietary fiber
inclusion promotes the proliferation of these microorganisms. Their
predominance in the GIT, particularly in the colon, is directly related to the
proportion of fiber in the diet.
The role of fiber in
Fiber has both direct and
indirect effects of GIT health. Some of these benefits have been known for
decades, if not centuries. The most obvious is its anti-constipation bulking
effect. Pectin, which is generally added in small amounts of a tablespoon or
less, provides bulk because it swells after mixing with digesta. It also
promotes the proliferation of beneficial microorganisms. Because of this latter
property, it can also be categorized as a prebiotic .
Highly soluble fibers such
as pectin have the additional benefit of stopping diarrhea. Their ability to
quickly absorb water on contact allows them to thicken digesta. Pectin only
works while it passes through the GIT, it must be continually replaced to
maintain this anti-diarrheal effect. It is better to consume smaller doses of
pectin throughout the day than take the full dose only once. Pectin treats
symptoms; it does not necessarily address the cause of the diarrhea.
A less well-known
attribute of fiber is its ability to trap molecules within its matrix. These
molecules are then carried through the colon and excreted in the feces. Two
notable substances have been suggested to be removed by this process:
ammonia/urea (Corley et al., 1978; Fahey, 1976) and cholesterol.
Nitrogen, which is a
by-product of protein digestion, is generally excreted as ammonia in the urine.
After it is released from protein, the nitrogen is absorbed through the GIT
membrane as urea, which is actually two ammonia molecules stuck together. It
then makes its way to the kidneys for excretion in the urine.
The entrapping fiber
matrix prevents a significant amount of ammonia from being absorbed into the
bloodstream, and is excreted via the feces instead. Likewise, cholesterol
molecules are trapped within the GIT and excreted in the feces (Roberfroid and
Stress and the
gastrointestinal tract microflora
Stress has both direct and
indirect effects on the GIT microflora (Tannock, 1983). Stress-induced hormones
can change GIT pH and cause cessation of active nutrient movement. Part of the
flight-or-fight mechanism inherent in all mammals re-directs available energy to
the muscles. This can result in complete or partial GIT shut down, which
involves both the secretion of enzymes and nutrient flow. Both pH changes and
cessation of nutrient flow detrimentally impact indigenous microflora. The
severity of the stress will determine the extent of the damage.
Another side effect of the
reduction in enzyme activity is the predominance of highly digestible material
that makes its way into the colon. This situation can simulate symptoms of
exocrine pancreatic insufficiency (EPI).
present both a physical and chemical barrier and actively combat pathogens.
They are the first line of defense against pathogens which enter the host
orally. Along with a healthy immune system, indigenous microflora prevent the
proliferation of opportunistic pathogens. Antibiotics can strip the GIT of this
Potential uses for
pectin in medical practice
Diarrhea is a very serious
and debilitating condition. If left unchecked, diarrhea can kill. I have used
pectin to control diarrhea in a variety of mammalian species, both livestock and
pets. Pectin by itself is not enough to permanently control diarrhea. The
first victims of this condition are the GIT microflora. Long-term treatment
involves both the cessation of nutrient and electrolyte loss, as well as the
replacement of the indigenous microorganisms. Probiotic microorganisms
temporary fill the physical and chemical roles performed by the indigenous
microflora. They also allow these beneficial microorganisms to proliferate.
Illnesses such as
irritable bowel syndrome (IBS), are marked by chronic diarrhea. I have used a
combination of pectin and probiotics to control and reverse this stress-induced
disease in dogs. People and dogs who suffer from EPI often have chronic
diarrhea. This is a result of highly digestible material reaching the colon.
Normally, less than 5% of these food components survive passage of the small
intestine Highly digestible material selects for colon microflora which cause
diarrhea and may be detrimental to the host in other ways.
that promote the development or urinary calculi are ameliorated by the
entrapment ability of fiber in general, and pectin in particular. The
entrapment quality of a fiber is enhanced by its degree of solubility.
In addition, recent
research (Ou Limm, et al., 1997) suggests that pectin may trap the
immunoglobulin responsible for triggering allergy symptoms (IgE). Animal trials
at Natur s Way, Inc. show that most dogs show reduced allergy symptoms when fed
a pectin-based probiotic.
Because pectin absorbs
moisture very quickly, it swells. If this swelling occurs in the esophagus, it
can trigger regurgitation. Dogs should be fed pectin in the dry form, either on
dry food or on a dry treat.
Pectin is inert to the
host, it has no side effects and remains within the confines of the GIT. It
needs to be replenished on a daily basis to provide continuous benefit. Pectin
combined with a daily probiotic supplement will encourage GIT health.
Complicating conditions such as IBS and EPI will determine the probiotic
MSE Natural Defense is a
hypoallergenic pectin-based probiotic supplement for pets. It is made from
food-grade pectin and pure microbial cultures (3.0 x 108 cfu/g). It
is available either directly from Natur s Way, Inc. (800-615-0299) or on
amazon.com. Free samples are available upon request (firstname.lastname@example.org).
Corley, J. R, R. A.
Easter, M. A. Roos and G. C. Fahey. 1978. Effect of various fiber sources on
gain, feed efficiency and nitrogen retention in the weanling pig. Nutr. Rep.
Internat l 18:135.
Fahey, G. C. 1976.
Factors influencing the utilization and digestibility of hemicellulose.
Doctoral dissertation, West Virginia University, Morgantown.
1997. Dietary Fibers Modulate Indices of Intestinal Immune Function in Rats. J.
Roberfroid and N. Delzenne.
1995. Oligofructose supplemented diet lowers serum and VLDL concentrations,
triglycerides, phospholipids and cholesterol in rats. Lipids 163-167.
Tannock, G. W. 1983.
Effect of dietary and environmental stress on the gastrointestinal microbiota.
In: Human intestinal microflora in health and disease (Hertges, D. J., ed.), pp.
517 539, Academic Press, New York, NY