Fibre has long been recognized for helping with digestive regularity and occasional constipation, however the advantages of a fibre-rich diet go far beyond these basic benefits.

In fact, diets low in saturated fat and cholesterol that include 7 grams of soluble fiber per day from psyllium seed husk may reduce the risk of heart disease.

In addition, a diet rich in fibre:

• Can contribute to a sense of fullness which may prevent over-eating and help you regulate your weight.
• Can promote the growth of your healthy bacteria and the food they need to thrive, which may help enhance your immune system’s ability to promote good immune health.
• Can slow your absorption of sugars, which has the potential to promote healthy blood glucose levels.
• Can add “bulk” to your stool as it supports regularity and elimination.

As you can quickly see with even this short list of benefits, fibre has entered the scene as a major player in your health and wellbeing.

So, the question then becomes obvious:

Are You Getting Your Daily Fibre requirements?

It doesn’t matter your age – getting the recommended allowance of fibre is an important part of your daily diet.

But, do you even know how much is the right amount? If you don’t, you’re not alone. A recent survey by the National Fiber Council showed that 88 percent of Americans have no idea how many grams of fiber they need a day.

This is one instance where ignorance is not bliss. In fact, the Columbia Institute of Human Nutrition reports that only 10 percent of all Americans get the recommended amount of fiber in their daily diet. And, what’s worse – the average American only eats about half the recommended fiber they need.

But we shouldn’t be all that surprised by these startling numbers because – even if we don’t want to admit it – most of us don’t really have a good handle on our fibre needs.

A 2005 national study revealed that over 50% of Americans think steak is high in fiber – but in reality meat has little or no fiber.
The same study discovered that one in five people has no idea how much fiber they eat daily — and nearly 60 percent of all respondents in the survey have never talked with their health care provider about fiber.

Again, it really should come as no surprise that most people have no idea how much fiber is needed daily.

So, how much fiber do you need and where can you get it?

When it comes to fiber, 32 grams is your minimum magic number. That’s the amount of recommended fiber you should consume daily.

But, if you’re like most, you’re likely only getting 10-15 grams – and yes, I know, it’s pretty shocking, isn’t it?

Plus, if you’re on a low carb diet or just don’t consume many fruits, vegetables or grains, you’re probably even further from your magic number. According to the Annals of Internal Medicine, people on low carb diets typically get only seven to eight grams of fiber daily!

I’ll let you do the math, but it should be obvious: For your optimal health and wellbeing, you can’t go wrong with adding more fiber into your daily diet.

Ideally, your diet will have foods high in soluble and insoluble fiber, including:

• dried beans
• peas
• flax seed
• green beans
• cauliflower

But, with the hustle and bustle of daily life, it’s often difficult to get the optimal amount of fiber you need.

• Soluble fiber  can propel food, sugars, cholesterol and fats cleanly through your digestive tract. Importantly, soluble fiber can contribute beneficially to your heart health and has been shown to lower cholesterol.
• Insoluble fiber acts as a bulking agent to improve your digestive regularity and to move food quickly through your colon.

In fact, clinical studies have shown that, when taken daily as a part of a diet low in saturated fat and cholesterol, 7 grams of soluble fiber from psyllium may help reduce heart disease risk by helping to lower cholesterol – both total cholesterol and LDL cholesterol levels.

So, it doesn’t matter whether you’re in your thirties or sixties, man or woman, I believe that now is the right time for you to start taking your heart health seriously.

The ‘probiotic difference’ you deserve

There are trillions of microorganisms that live in your digestive system – some are good,  but others do not provide any benefit. When it comes to your health and wellbeing, they play an incredibly important role and your fiber intake can make a big difference.

“Beneficial flora” are microorganisms that assist with digestion and absorption of your food, help strengthen your immune system, and contribute to your body’s overall heath and function.

Since  less desirable flora in the gut must compete with the helpful microbes already in residence, daily probiotic use can be an effective measure to help us keep the balance of intestinal flora tipped in favor of beneficial flora.

Probiotics are foods and supplements that actually contain these living beneficial microbes. Probiotics can help support your body’s natural and healthy flora and support a healthy balance.

How does all this relate to fiber?

Beneficial bacteria love to feed on fiber. Whereas, less desirable bacteria like to eat refined sugars and fats

Dietary fiber is found in plants. While all plants contain some fiber, plants with high fiber concentrations are generally the most practical source.

fiber-rich plants can be eaten directly. Or, alternatively, they can be used to make supplements and fiber-rich processed foods.

The American Dietetic Association (ADA) recommends consuming a variety of fiber-rich foods.

Legumes contain healthful dietary fibers.

Some plants contain significant amounts of soluble and insoluble fiber. For example plums (or prunes) have a thick skin covering a juicy pulp. The plum’s skin is an example of an insoluble fiber source, whereas soluble fiber sources are inside the pulp.[4]

Soluble fiber is found in varying quantities in all plant foods, including:

• legumes (peas, soybeans, lupins and other beans)
• oats, rye, chia, and barley
• some fruits and fruit juices (including prune juice, plums, berries, bananas, and the insides of apples and pears)
• certain vegetables such as broccoli, carrots, and Jerusalem artichokes
• root tubers and root vegetables such as sweet potatoes and onions (skins of these are sources of insoluble fiber)
• psyllium seed husk (a mucilage soluble fiber).

Sources of insoluble fiber include:

• whole grain foods
• wheat and corn bran
• nuts and seeds
• potato skins
• flax and hemp seed
• lignans
• vegetables such as green beans, cauliflower, zucchini (courgette), celery, and nopal
• some fruits including avocado, and bananas
• the skins of some fruits, including kiwifruit and tomatoes[5]

fiber supplements
These are a few example forms of fiber that have been sold as supplements or food additives. These may be marketed to consumers for nutritional purposes, treatment of various gastrointestinal disorders, and for such possible health benefits as lowering cholesterol levels, reducing risk of colon cancer, and losing weight.

Soluble fiber supplements may be beneficial for alleviating symptoms of irritable bowel syndrome, such as diarrhea and/or constipation and abdominal discomfort.[6] Prebiotic soluble fiber products, like those containing inulin or oligosaccharides, may contribute to relief from inflammatory bowel disease,[7] as in Crohn’s disease,[8] ulcerative colitis,[9][10] and Clostridium difficile,[11] due in part to the short-chain fatty acids produced with subsequent anti-inflammatory actions upon the bowel.[12][13] fiber supplements may be effective in an overall dietary plan for managing irritable bowel syndrome by modification of food choices.[14]

Inulins
Chemically defined as oligosaccharides occurring naturally in most plants, inulins have nutritional value as carbohydrates, or more specifically as fructans, a polymer of the natural plant sugar, fructose. Inulin is typically extracted by manufacturers from enriched plant sources such as chicory roots or Jerusalem artichokes for use in prepared foods.[15] Subtly sweet, it can be used to replace sugar, fat, and flour, is often used to improve the flow and mixing qualities of powdered nutritional supplements, and has significant potential health value as a prebiotic fermentable fiber.[16]

Inulin is advantageous because it contains 25–30% the food energy of sugar or other carbohydrates and 10–15% the food energy of fat. As a prebiotic fermentable fiber, its metabolism by gut flora yields short-chain fatty acids (discussed above) which increase absorption of calcium,[17] magnesium,[18] and iron,[19] resulting from upregulation of mineral-transporting genes and their membrane transport proteins within the colon wall. Among other potential beneficial effects noted above, inulin promotes an increase in the mass and health of intestinal Lactobacillus and Bifidobacterium populations.

Vegetable gums
Vegetable gum fiber supplements are relatively new to the market. Often sold as a powder, vegetable gum fibers dissolve easily with no aftertaste. In preliminary clinical trials, they have proven effective for the treatment of irritable bowel syndrome.[20] Examples of vegetable gum fibers are guar gum and acacia Senegal gum.

Mechanism

The main action of dietary fiber is to change the nature of the contents of the gastrointestinal tract, and to change how other nutrients and chemicals are absorbed.[1][2] Soluble fiber binds to bile acids in the small intestine, making them less likely to enter the body; this in turn lowers cholesterol levels in the blood.[3] Soluble fiber also attenuates the absorption of sugar, reduces sugar response after eating, normalizes blood lipid levels and, once fermented in the colon, produces short-chain fatty acids as byproducts with wide-ranging physiological activities (discussion below). Although insoluble fiber is associated with reduced diabetes risk, the mechanism by which this occurs is unknown.[21]

Not yet formally proposed as an essential macronutrient, dietary fiber is nevertheless regarded as important for the diet, with regulatory authorities in many developed countries recommending increases in fiber intake.[1][2][22][23]

Effects of fiber intake

Research has shown that fiber may benefit health in several different ways. Lignin and probably related materials that are resistant to enzymatic degradation, diminish the nutritional value of foods.[24]

Dietary fiber functions and benefits

Current recommendations from the United States National Academy of Sciences, Institute of Medicine, suggest that adults should consume 20–35 grams of dietary fiber per day, but the average American’s daily intake of dietary fiber is only 12–18 grams.[34][35]

The ADA recommends a minimum of 20–35 g/day for a healthy adult depending on calorie intake (e.g., a 2000 Cal/8400 kJ diet should include 25g of fiber per day). The ADA’s recommendation for children is that intake should equal age in years plus 5 g/day (e.g., a 4 year old should consume 9 g/day). No guidelines have yet been established for the elderly or very ill. Patients with current constipation, vomiting, and abdominal pain should see a physician. Certain bulking agents are not commonly recommended with the prescription of opioids because the slow transit time mixed with larger stools may lead to severe constipation, pain, or obstruction.

The British Nutrition Foundation has recommended a minimum fiber intake of 18 g/day for healthy adults.[36]

Fiber recommendations in North America

On average, North Americans consume less than 50% of the dietary fiber levels recommended for good health. In the preferred food choices of today’s youth, this value may be as low as 20%, a factor considered by experts as contributing to the obesity levels seen in many developed countries.[37][38]

Recognizing the growing scientific evidence for physiological benefits of increased fiber intake, regulatory agencies such as the Food and Drug Administration (FDA) of the United States have given approvals to food products making health claims for fiber.

In clinical trials to date, these fiber sources were shown to significantly reduce blood cholesterol levels, an important factor for general cardiovascular health,[39] and to lower risk of onset for some types of cancer.[40]

Soluble (fermentable) fiber sources gaining FDA approval are:

• Psyllium seed husk (7 grams per day)
• Beta-glucan from oat bran, whole oats, oatrim, or rolled oats (3 grams per day)
• Beta-glucan from whole grain or dry-milled barley (3 grams per day)

Other examples of fermentable fiber sources (from plant foods or biotechnology) used in functional foods and supplements include inulin, resistant dextrins, fructans, xanthan gum, cellulose, guar gum, fructooligosaccharides (FOS), and oligo- or polysaccharides.

Consistent intake of fermentable fiber through foods like berries and other fresh fruit, vegetables, whole grains, seeds, and nuts is now known to reduce risk of some of the world’s most prevalent diseases[41][42][43][44]—obesity, diabetes, high blood cholesterol, cardiovascular disease, and numerous gastrointestinal disorders. In this last category are constipation, inflammatory bowel disease, ulcerative colitis, hemorrhoids, Crohn’s disease, diverticulitis, and colon cancer—all disorders of the intestinal tract where fermentable fiber can provide healthful benefits.[41]

Insufficient fiber in the diet can complicate defecation.[45] Low-fiber feces are dehydrated and hardened, making them difficult to evacuate—defining constipation[45] and possibly leading to development of hemorrhoids[45] or anal fissures.

Although many researchers believe that dietary fiber intake reduces risk of colon cancer, one study conducted by researchers at the Harvard School of Medicine of over 88,000 women did not show a statistically significant relationship between higher fiber consumption and lower rates of colorectal cancer or adenomas.[46]

‘Dietary fiber’ has been used as a collective term for a complex mixture of substances with different chemical and physical properties which exert different types of physiological effects. The use of certain analytical methods to quantify ‘dietary fiber’ by nature of its indigestibility results in many other indigestible components being isolated along with the carbohydrate components of dietary fiber. These components include resistant starches and oligosaccharides along with other substances that exist within the plant cell structure and contribute to the material that passes through the digestive tract. Such components are likely to have physiological effects. Yet, some differentiation has to be made between these indigestible plant components and other partially digested material, such as protein, that appears in the large bowel. Thus, it is better to classify fiber as a group of compounds with different physiological characteristics, rather than to be constrained by defining it chemically.

Diets naturally high in fiber can be considered to bring about several main physiological consequences:

• helps prevent constipation
• reduces the risk of colon cancer
• improvements in gastrointestinal health
• improvements in glucose tolerance and the insulin response
• reduction of hyperlipidemia, hypertension, and other coronary heart disease risk factors
• reduction in the risk of developing some cancers
• increased satiety and hence some degree of weight management

Therefore, it is not appropriate to state that fiber has a single all encompassing physiological property as these effects are dependent on the type of fiber in the diet. The beneficial effects of high fiber diets are the summation of the effects of the different types of fiber present in the diet and also other components of such diets. Defining fiber physiologically allows recognition of indigestible carbohydrates with structures and physiological properties similar to those of naturally occurring dietary fibers.[48]

Fiber, a type of carbohydrate, contributes less energy (measured in Calories or kilojoules) than sugars and starches because it cannot be fully absorbed by the body. Sugars and starches provide 4 Calories per gram, and the human body has specific enzymes to break them down into glucose, fructose, and galactose, which can then be absorbed by the body. The human body lacks enzymes to break down fiber. Insoluble fiber does not change inside the body, so the body cannot absorb it and nutritionists say that it contributes 0 Calories per gram.

Soluble fiber is partially fermented, with the degree of fermentability varying with the type of fiber, and contributes some energy when broken down and absorbed by the body. Dietitians have not reached a consensus on how much energy is actually absorbed, but some approximate around 2 Calories (8.5 kilojoules) per gram of soluble fiber. Regardless of the type of fiber, the body absorbs fewer than 4 Calories (16.7 kilojoules) per gram of fiber, which can create inconsistencies for actual product nutrition labels. In some countries, fiber is not listed on nutrition labels, and is considered 0 Calories/gram when the food’s total Calories are computed.

In other countries all fiber must be listed, and is considered 4 Calories per gram when the food’s total Calories are computed (because chemically fiber is a type of carbohydrate and other carbohydrates contribute 4 Calories per gram). In the US, soluble fiber must be counted as 4 Calories per gram, but insoluble fiber may be (and usually is) treated as 0 Calories per gram and not mentioned on the label.

Soluble fiber fermentation

The American Association of Cereal Chemists has defined soluble fiber this way: “the edible parts of plants or similar carbohydrates resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine.”[49] In this definition:

Edible parts of plants – indicates that some parts of a plant we eat—skin, pulp, seeds, stems, leaves, roots—contain fiber. Both insoluble and soluble sources are in those plant components.

Carbohydrates – complex carbohydrates, such as long-chained sugars also called starch, oligosaccharides, or polysaccharides, are sources of soluble fermentable fiber resistant to digestion and absorption in the human small intestine

Foods providing nutrients are digested by gastric acid and digestive enzymes in the stomach and small intestine where the nutrients are released then absorbed through the intestinal wall for transport via the blood throughout the body. A food resistant to this process is undigested, as insoluble and soluble fibers are. They pass to the large intestine only affected by their absorption of water (insoluble fiber) or dissolution in water (soluble fiber).

Complete or partial fermentation in the large intestine. the large intestine comprises a segment called the colon within which additional nutrient absorption occurs through the process of fermentation. Fermentation occurs by the action of colonic bacteria on the food mass, producing gases and short-chain fatty acids. It is these short-chain fatty acids—butyric, acetic (ethanoic), propionic, and valeric acids—that scientific evidence is revealing to have significant health properties.[50]

As an example of fermentation, shorter-chain carbohydrates (a type of fiber found in legumes) cannot be digested, but are changed via fermentation in the colon into short-chain fatty acids and gases (which are typically expelled as flatulence).

According to a 2002 journal article,[41] fibers compounds with partial or low fermentability include:

• cellulose, a polysaccharide
• hemicellulose, a polysaccharide
• lignans, a group of phytoestrogens
• plant waxes
• resistant starches

Fiber compounds with high fermentability include:

• beta-glucans, a group of polysaccharides
• pectins, a group of heteropolysaccharides
• natural gums, a group of polysaccharides
• inulins, a group of polysaccharides
• oligosaccharides, a group of short-chained or simple sugars
• resistant dextrins[51]

Short-chain fatty acids

When soluble fiber is fermented, short-chain fatty acids (SCFA) are produced. SCFAs are involved in numerous physiological processes promoting health, including:[50]

• stabilize blood glucose levels by acting on pancreatic insulin release and liver control of glycogen breakdown
• stimulate gene expression of glucose transporters in the intestinal mucosa, regulating glucose absorption[52]
• provide nourishment of colonocytes, particularly by the SCFA butyrate
• suppress cholesterol synthesis by the liver and reduce blood levels of LDL cholesterol and triglycerides responsible for atherosclerosis
• lower colonic pH (i.e., raises the acidity level in the colon) which protects the lining from formation of colonic polyps and increases absorption of dietary minerals
• stimulate production of T helper cells, antibodies, leukocytes, cytokines, and lymph mechanisms having crucial roles in immune protection
• improve barrier properties of the colonic mucosal layer, inhibiting inflammatory and adhesion irritants, contributing to immune functions

SCFAs that are absorbed by the colonic mucosa pass through the colonic wall into the portal circulation (supplying the liver), and the liver transports them into the general circulatory system.

Overall, SCFAs affect major regulatory systems, such as blood glucose and lipid levels, the colonic environment, and intestinal immune functions.[53][54]

The major SCFAs in humans are butyrate, propionate, and acetate, where butyrate is the major energy source for colonocytes, propionate is destined for uptake by the liver, and acetate enters the peripheral circulation to be metabolized by peripheral tissues.

FDA-approved health claims

The FDA allows producers of foods containing 1.7g per serving of psyllium husk soluble fiber or 0.75g of oat or barley soluble fiber as beta-glucans to claim that reduced risk of heart disease can result from their regular consumption.[55]

The FDA statement template for making this claim is: Soluble fiber from foods such as [name of soluble fiber source, and, if desired, name of food product], as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. A serving of [name of food product] supplies __ grams of the [necessary daily dietary intake for the benefit] soluble fiber from [name of soluble fiber source] necessary per day to have this effect.[55]

Eligible sources of soluble fiber providing beta-glucan include:

1. Oat bran
2. Rolled oats
3. Whole oat flour
4. Oatrim
5. Whole grain barley and dry milled barley
6. Soluble fiber from psyllium husk with purity of no less than 95%

The allowed label may state that diets low in saturated fat and cholesterol and that include soluble fiber from certain of the above foods “may” or “might” reduce the risk of heart disease.

As discussed in FDA regulation 21 CFR 101.81, the daily dietary intake levels of soluble fiber from sources listed above associated with reduced risk of coronary heart disease are:

• 3g or more per day of beta-glucan soluble fiber from either whole oats or barley, or a combination of whole oats and barley
• 7g or more per day of soluble fiber from psyllium seed husk.[56]

Soluble fiber from consuming grains is included in other allowed health claims for lowering risk of some types of cancer and heart disease by consuming fruit and vegetables (21 CFR 101.76, 101.77, and 101.78).[55]