Bloating, gas, constipation, energy spikes and crashes, brain fog, feeling hungry when you shouldn’t be, and catching every cough, cold and flu that crosses your path…

Feel familiar?

These persistent symptoms trace back to the state of our gut health and digestion, and a lack of fiber can play a role.

Trillions of bacteria form a diverse ecosystem in our gastrointestinal (GI) tract - your gut microbiome. This bacteria plays a pivotal role in our physiological functioning, and loves fiber!

Fiber is the foundation of a resilient gut microbiome. Let’s dig in!

Dietary fiber is sourced from plants - fruits, vegetables, nuts, seeds, herbs, spices, beans, peas and lentils. It’s crucial for digestion and absorption of nutrients, let alone our overall gastrointestinal and metabolic health!

Fiber provides a food source for our beneficial gut bacteria living in our colon. These bacteria digest and ferment fiber, producing anti-inflammatory metabolites called ‘short-chain fatty acids’ (SCFAs) like butyrate, acetate and propionate. In return, SCFAs act as a food/energy source for our colonic cells, fuelling our gut microbiome’s daily activities. The functions of SCFAs are wide-reaching, including supporting mucus production protective of our gut lining, metabolism, insulin sensitivity, immune function, cell growth and division, and maintenance of ideal cholesterol levels.

Low intake of dietary fiber is a risk factor for chronic, systemic inflammation. The emergence and continued presence of the ‘Western’ diet translates to much food production lacking fiber and nutritional value. As a result, the incidence of metabolic disorders has become more pronounced over time. Research continues to show clear connections between insufficient dietary fiber intake and disease states.

Both beneficial and ‘poor’ bacteria live in our gut microbiome. Poor bacterial strains in the gut are naturally-occurring, becoming problematic when overgrown. This results in a state of gut ‘dysbiosis’ - high levels of poor bacteria, and low levels of beneficial bacteria struggling to survive. Gut dysbiosis is a precursor with digestive and overall health disorder. A healthy gut microbiome is not only about the ratio of beneficial to poor, it’s about diversity of bacterial strains, too!

Fortunately, our gut microbiome is modifiable, both through nutritional and lifestyle behaviours. Build a solid foundation with a diverse, colourful, anti-inflammatory, whole food diet! Then, layer in strategic supplementation for periods of time, as your unique health needs dictate. 

 

KEY FORMS OF FIBER FOR YOUR GUT MICROBIOME

 

Soluble Fiber

• Attracts water into the intestinal tract, turning it into a gel-like substance
• Slows down digestion and nutrient absorption from the stomach and small intestine
• Feeds beneficial gut bacteria in our large intestine, fuelling our gut microbiome
• Keeps you full for an extended period of time, supporting blood sugar stabilization
• Helps to bulk up/soften stools for elimination (easier-to-pass poops!)
• Found in apple, apricot, asparagus, avocado, berries, broccoli, Brussels sprouts, carrot, chia/flax/sunflower seeds, citrus, legumes, onion, pear, walnuts, oats (ideally organic/gluten-free-sourced), peach, plum, sweet potato, turnip, whole grains…

 

Insoluble Fiber

• Roughage that remains intact (undigested) as it passes through the digestive tract
• Supports the passage of food through the stomach and intestines, preventing constipation and ensuring comfortable ‘transit time’ toward elimination
• Acts like a broom - sweeps along ‘debris’ within the intestinal tract
• Draws water into and helps bulk up stools for elimination, keeping you ‘regular’! 
• Found in almonds, apples/pears (skin on), banana, Bell pepper, berries, broccoli, cauliflower, celery, cucumber, dark/leafy greens, grapes, green beans, legumes, nuts/seeds, onion, orange, potato, root vegetables and their skins, whole grains, zucchini…

 

Resistant Starch

• Resists digestion in the small intestine, so as to be fermented by beneficial gut bacteria in the large intestine, instead!
• Prebiotic fiber that fuels the gut microbiome’s activity
• Doesn’t spike blood sugar levels, supporting insulin sensitivity
• Cooking and cooling starches increases their resistant starch content; reheating them does not negatively impact this content
• Found in: cooked and cooled potatoes, cooked and cooled rice, legumes, slightly green (unripe) bananas and plantain, and raw oats (e.g. overnight oats) (ideally an organic, gluten-free source)

 

Polyphenol-Rich Fiber

• Binds to fiber so it doesn’t get digested early on in the stomach, reaching the large intestine for fermentation and production of SCFAs, instead!
• Prebiotic fiber that builds diversity with your gut microbes
• Powerful sources of antioxidants - counter oxidative stress impacting cell/tissue integrity
• Found in berry varieties, dark chocolate, grapes, green tea, high-quality extra-virgin olive oil, nuts/seeds, plums, pomegranate…

 

The ‘biotics’ trio - PREbiotics, PRObiotics and POST-biotics - play a critical role, too!

 

Prebiotics

• Indigestible fiber that fertilizes our gut, feeding beneficial gut bugs in the large intestine 
• All prebiotics are fiber-like, but not all fiber is prebiotic fiber
• Found in apple (tart, green), asparagus, banana (slightly green or turned yellow), brown rice, chicory and dandelion greens/root, ground flax seed, garlic (especially raw), green banana, Jerusalem artichoke, jicama, kiwi, leek, legumes, oats (ideally organic, gluten-free-sourced), onion (especially raw), seaweeds…
• May also appear on labels as inulin, fructooligosaccharides (FOS) and galactooligosaccharides (GOS)
• *Exercise caution if navigating digestive conditions, like IBS and SIBO

 

Probiotics

• • Live, beneficial organisms (e.g. Lactobacillus and Bifidobacterium strains) gained from food or supplement form that support digestion, elimination, immunity and otherwise
  • Reduce the flow of inflammatory toxins from the intestinal tract to the liver
  • Support bulking up/softening of stools and elimination of toxins and waste 
  • Found in raw, unpasteurized ferments, including: sauerkraut, kimchi, miso, tempeh, (low-sugar) kombucha, yogurt and lacto-fermented veggies
  • Raw ferments are very concentrated; start slow and monitor your bowels/digestive response 
  • A supplement containing strains that address your needs can complement your whole food foundation
  • *Exercise caution if navigating digestive conditions, like SIBO and histamine intolerance

 

Postbiotics

• Beneficial metabolic by-products created when gut bacteria ferment fiber in the colon
  • E.g. butyrate, acetate and propionate (SCFAs)
• Fuel large intestinal function, strengthen the intestinal lining, and help make the gut more resilient to poor bacteria and disease-causing organisms
• The reward of a diverse, colorful, fiber-rich diet aligned with your health circumstances!

 

STRATEGIC FIBER SUPPLEMENTATION

 

This serves the purpose of ensuring a fiber baseline day-to-day, particularly if fiber intake from whole foods really fluctuates.

 

Examples include:

 

• Psyllium husk
  • Soluble fiber that attracts water, thickening to form a gel-like substance
  • Support constipation and blood sugar/cholesterol management
  • Available in loose powder or capsule form
  • *Start with a small volume (e.g. 1 tsp. in a tall glass of water),  remain very well hydrated, and monitor bowel response 

• Ground flax seed/sprouted ground flax seed
  • Soluble and insoluble fiber and anti-inflammatory, Omega-3 fatty acids
  • Supports constipation and estrogen metabolism
  • *Start with a small volume (e.g. 1 tsp. in a smoothie or sprinkled on food), and gradually increase to 1-2 tbsp. daily, for example

• Chia seed
  • Soluble fiber that attracts water, thickening to form a gel-like substance
  • Helps bulk up and soften stools, promoting regularity
  • *Enjoy in a chia pudding, for example

• Dandy Blend (naturally gluten-free, herbal coffee substitute)
  • Contains inulin - prebiotic fiber found within this blend of dandelion and chicory root
  • *Exercise caution if navigating digestive conditions, like IBS and SIBO

These key forms of fiber ALL MATTER. They work in synergy with one another, within our gut ecosystem. Nothing works in isolation.

 

DAILY FIBER TARGETS

• Men
  • 38g (19-50 yrs)
  • 30g (51+ yrs)
• Women
  • 25g (19-50 yrs)
  • 21g (51+ yrs) 
• Pregnancy and lactation
  • 28-29g (any age)
• Children and adolescents:
  • 19g (children 1-3 yrs)
  • 31-38g (boys 9-18 yrs)
  • 25-26g (girls 9-18 yrs)

 

To achieve your daily (minimum) fiber target, ensure plants are the star of your three main meals:

• ½-¾ of your plate = colourful plant fiber
• ¼ of your plate = whole food-based, starchy carbohydrate 
• ¼ of your plate =  protein
• A source of anti-inflammatory fat (e.g. culinary oil, avocado, nuts/seeds)

 

PRACTICAL WAYS TO BE IN THE KNOW WITH YOUR FIBER INTAKE

 

Assess your weekly fiber by tracking your sources, intake and bowel movements for one week.

• How many different types did you consume?
• What colours?
• Did you enjoy some fiber at each of your main meals and with any snacks?
• How frequent were your bowel movements, and what were they like?

This is an invaluable way of doing a beginning self-assessment.

 

What are your next steps?

• Gradually increase the diversity? (types and colours)
• Gradually increase intake throughout the day?
• Gradually increase your water intake, too?

 

Lean on cost-effective fiber sources:

• Dried legumes (beans, peas and lentils) 
• Frozen fruit
• Frozen vegetables
• Produce on sale (can freeze, if applicable, for later)
• Produce currently in season

 

TIPS

 

Increasing fiber intake must be gradual, so that you don’t overwhelm your system! Spread fiber increases over a few week’s time or more (e.g. a few grams every few days). Monitor your body’s response (e.g. digestion during/after meals and bowel movements), so your gut bacteria and digestive tract can more easily adapt.

Adequate hydration is essential, as water helps fiber move through the intestines to prevent stagnation and constipation. Strive for minimum half your body weight in ounces of water daily, accounting for more if consuming caffeine, exercising and/or perspiring.

 

IF THINGS DON’T GO ACCORDING TO PLAN…

 

Increasing fiber intake too quickly can lend to bloating, gas, cramping, constipation and general gastrointestinal discomfort, given gut bacteria are attempting to break down and ferment all fiber coming in. Should this occur, reduce your fiber intake back to your previous norm, and hold steady at that intake until the digestive system re-regulates to your previous normal.

If you’re having trouble digesting particular types of fiber, whether raw or cooked, this is something to investigate with your practitioner. It can be an indication of deeper, underlying issues and imbalances going on in the gut.

 

SOURCES

Dietary Fibre Modulates the Gut Microbiota

Effects of Dietary Fibers on Short-Chain Fatty Acids and Gut Microbiota Composition in Healthy Adults: A Systematic Review

HealthLinkBC: Fiber and Your Health

Microbiome Gut-Brain Axis: Impact on Brain Development and Mental Heath

Soluble Dietary Fiber, One of the Most Important Nutrients for the Gut Microbiota

The Health Benefits of Dietary Fibre

The Role of Dietary Fiber in Health Promotion and Disease Prevention: A Practical Guide for Clinicians