The gut Reset Series – Part 3

Protein

Protein needs are often treated as universal, but ancestral adaptation plays a significant role in how efficiently different bodies process this macronutrient.

Northern climate adaptation. Populations that evolved in Northern Europe, Scandinavia, and Arctic regions spent generations relying heavily on animal protein and fat when carbohydrates were scarce during long winters. This selective pressure resulted in:

• Higher resting metabolic rate (RMR): Caucasians tend to have an RMR approximately 5% higher than people of African descent – an adaptation for internal heat generation in cold environments. Higher metabolic rate means higher caloric and protein demands.
• Genetic selection for protein metabolism: Variants favouring efficient energy extraction from animal protein became more common in these populations.
• Stronger protein-sparing effects from animal sources: Cold-adapted bodies appear to retain lean muscle mass more effectively from meat and fish than from plant proteins.

Tropical and sub-tropical adaptation. Populations from Africa, the Caribbean, and equatorial regions evolved under different pressures. Generating excess body heat was a liability, not an advantage, leading to:

• Lower resting metabolic rate: A more efficient “cooler engine” that conserves energy rather than burning it for warmth.
• Greater protein efficiency: Research on nitrogen balance suggests these populations extract amino acids effectively from moderate-protein diets. Higher fecal nitrogen in some studies indicates the body takes what it needs and discards excess rather than struggling to meet requirements.
• Ancestral diets rich in fish, poultry, and plants: When people of African descent shift to high-red-meat Western diets, they experience significantly higher inflammation compared to other groups – suggesting their systems are tuned for leaner protein sources.

The practical takeaway. Protein needs exist on a spectrum shaped by ancestral geography. Those with Northern European ancestry may genuinely require more total protein – particularly from animal sources – to support their higher metabolic baseline. Those with tropical or sub-tropical ancestry often thrive on moderate protein intake emphasizing fish, poultry, legumes, and plant sources, and may experience more inflammation when red meat dominates.

Yeast Foods

Yeast-containing foods such as bread, pasta, baked goods, beer, and wine can be difficult for some individuals when eaten in excess or too frequently. Refined grain products are rapidly broken down into sugar, which may feed unwanted yeast or bacterial overgrowth in the gut. These foods can also ferment during digestion, leading to bloating, gas, cravings, and sluggish digestion in sensitive individuals.

Sulfur Metabolism

Sulfur is a natural compound used in many body processes. It helps form amino acids, connective tissue, detoxification compounds, and antioxidants such as glutathione.

However, sulfur must be properly processed. If intake is high while detox pathways are sluggish, some people may accumulate irritating sulfur byproducts. Gut bacteria can also convert sulfur compounds into hydrogen sulfide gas, which in excess may contribute to:

• Gas
• Bloating
• Loose stools
• Irritation
• Strong body odor or gas odor
• Brain fog in some individuals

The inflammation connection. At low levels, hydrogen sulfide acts as a beneficial signaling molecule. At higher concentrations, it becomes cytotoxic – damaging the intestinal lining, impairing mitochondrial energy production, and triggering inflammatory cascades. People with sluggish sulfur detoxification, certain genetic variants, or dysbiotic gut flora are especially vulnerable to this tipping point.

Baseline matters. Because internal sulfur levels vary by genetics and ancestry, the same dietary sulfur load affects people differently. Someone with naturally high sulfur status adding garlic, eggs, and broccoli to every meal may push past their threshold, while another person with lower baseline levels handles those foods easily.

This does not mean sulfur foods are unhealthy – it means metabolism matters.

Free-floating vs. protein-bound sulfur. Not all dietary sulfur behaves the same way. Cruciferous vegetables and alliums (garlic, onions) contain sulfur in relatively “free” forms that gut bacteria quickly ferment into hydrogen sulfide gas – often causing rapid-onset bloating and discomfort in sensitive individuals. Animal foods like eggs and meat contain sulfur bound within protein structures (methionine and cysteine), which is released more gradually during digestion and directed toward tissue repair rather than bacterial fermentation. This is why some people tolerate eggs better than a large serving of broccoli, despite both being “sulfur foods.”

Dairy

Dairy can affect people through three main pathways: proteins, sugars, and hormone signaling.

• Milk proteins (casein/whey): May trigger immune irritation or inflammatory responses in sensitive individuals, contributing to congestion, mucus, skin flare-ups, or digestive discomfort.
• Lactose (milk sugar): If lactase enzyme levels are low, lactose remains undigested and ferments in the gut, causing bloating, gas, cramps, and loose stools.
• Insulin / IGF-1 signaling: Dairy may raise insulin and IGF-1 activity, which can stimulate oil glands, increase sebum production, and worsen acne or hormone-related skin concerns in some people.

It’s important to note that dairy tolerance exists on a spectrum. Some individuals may handle small amounts – especially fermented or higher-quality sources – without issue, while others notice symptoms even with minimal intake. Factors such as gut health, enzyme production, genetics, and overall inflammatory load all influence how the body responds.

Additionally, the type and quality of dairy matter. Processing methods, fat content, and how the animal was raised can all impact how the body reacts. Many commercial dairy products also contain added ingredients – such as colorants in certain cheeses or added sugars in flavored yogurts – which can further contribute to digestive stress, blood sugar fluctuations, and inflammation in sensitive individuals. For those experiencing persistent symptoms, a temporary removal followed by a structured reintroduction can help determine individual tolerance and guide long-term dietary choices.