The Science: How Bone Broth Supports Your Gut
Your gut wall is a single-cell-thick barrier — roughly the thickness of a human eyelash. When tight junction proteins (ZO-1, occludin, claudin-1) break down, undigested particles and bacterial endotoxins leak into your bloodstream. Researchers call this intestinal hyperpermeability. Most people call it feeling awful after every meal.
Bone broth works here through two mechanisms. First, glutamine — the primary fuel source for enterocytes (gut lining cells). Without enough glutamine, those cells can't replicate fast enough to maintain the barrier. Research shows glutamine directly upregulates the tight junction proteins that hold gut cells together. Second, glycine suppresses the NF-κB inflammatory pathway — the same pathway implicated in IBD — while reducing TNF-α and IL-6, the cytokines that drive gut inflammation.
A 2024 animal colitis study found bone broth produced 60–95% lower inflammatory markers versus controls. Human data using collagen peptides confirmed restoration of ZO-1 and occludin — the exact proteins that determine whether your gut leaks or holds.
Each 15g serving (3 scoops) of reGrounded delivers approximately 2.25g glutamine and 5g glycine — meaningful daily doses working on the barrier from two distinct angles.
Collagen makes up roughly 70–80% of your skin's dry weight. From your mid-20s, you lose approximately 1% of it every year. By 40, roughly 24% is gone. This isn't cosmetic — it's structural. Thinner dermis means less moisture retention, less elasticity, and slower wound repair.
The mechanism that makes bone broth work for skin isn't just "more collagen building blocks." It's more specific than that. When hydrolysed collagen is digested, dipeptides — primarily Pro-Hyp and Gly-Pro-Hyp — survive digestion intact and are absorbed via the PEPT1 transporter. These peptides reach the dermis and act as biological signals, instructing fibroblasts to upregulate collagen type I, elastin, versican, and hyaluronic acid synthesis. The cell doesn't just receive raw material — it receives an instruction to build.
The clinical evidence is among the strongest in nutritional science:
- 20% reduction in eye wrinkle volume at 8 weeks (Proksch et al., 2014)
- 65% increase in procollagen type I (Proksch et al., 2014)
- 28% improvement in skin hydration (Asserin et al., 2015)
- Meta-analysis of 26 RCTs across 1,721 patients confirmed significant improvements in hydration and elasticity (Pu et al., 2023)
Each 15g serving (3 scoops) delivers 12.75g collagen — in the range of doses used across these trials.
Most bone broth powders contain no added hyaluronic acid. reGrounded adds 100mg per serving (15g) — deliberately, because this is where the science pointed.
Hyaluronic acid is a glycosaminoglycan (GAG) that can hold up to 1,000 times its weight in water. In your skin, it sits in the extracellular matrix alongside collagen, acting as a moisture reservoir. As collagen declines, so does HA — the two fall together, which is why skin loses both structure and hydration simultaneously after 35.
The synergy is the point. Collagen peptides (specifically Pro-Hyp) have been shown to stimulate HA synthesis in skin cells roughly fourfold (Ohara et al., 2010). Adding 100mg of oral HA amplifies this further. Clinical studies on oral HA at this dose show measurable reductions in wrinkle volume and improved skin moisture at 8 weeks (Oe et al., 2017).
Oral HA is also being studied for its role in joint lubrication — synovial fluid is largely composed of hyaluronic acid, and its decline contributes to the friction and stiffness associated with joint deterioration. 100mg daily supports both skin and joint pathways simultaneously.
Glycine is the most abundant amino acid in bone broth approximately 5g per 15g serving of reGrounded, or roughly 33% of the collagen content. Most people have never heard of it. Most people are also chronically short of it.
Research from Meléndez-Hevia et al. (2009) estimated the average adult dietary glycine shortfall at 10g per day meaning the body's need for glycine consistently exceeds what diet plus endogenous synthesis can supply. This matters because glycine is doing several things at once.
Sleep: Glycine acts as an inhibitory neurotransmitter and lowers core body temperature at sleep onset — one of the primary physiological signals for initiating deep sleep. A double-blind trial showed 3g of glycine before bed significantly improved sleep quality and reduced next-day fatigue (Bannai et al., 2012). One 15g serving of reGrounded delivers that dose naturally.
Inflammation: Glycine binds glycine-gated chloride channels on macrophages, causing membrane hyperpolarisation that blunts immune cell overactivation. It suppresses TNF-α, IL-6, and IL-1β while upregulating anti-inflammatory IL-10. This is systemic anti-inflammatory action without any pharmaceutical intervention.
Glutathione: Glycine is the rate-limiting substrate for glutathione synthesis — the body's master antioxidant. Research confirms that tissue glycine levels sit below the Km of glutathione synthase, meaning more dietary glycine directly enables more antioxidant production (McCarty et al., 2018). Bone broth is the richest whole-food source of glycine available.
Cartilage has no blood supply. It receives nutrients through the synovial fluid surrounding it which means it depends entirely on what circulates in your body. When collagen peptides are absorbed, studies using radiolabelled Pro-Hyp show they localise specifically in cartilage tissue. Once there, chondrocytes (cartilage cells) use them both as raw material and as signalling molecules to upregulate matrix production.
The clinical data on joints is robust:
- 42% reduction in activity-related knee pain over 12 weeks in athletes (Zdzieblik et al., 2017)
- Significant improvement in joint function in osteoarthritis patients taking collagen hydrolysate over 24 weeks (Shaw et al., 2017)
reGrounded also provides approximately 2g arginine per serving (15g). Arginine is the substrate for nitric oxide production — which vasodilates blood vessels and improves circulation to nutrient-poor tissues like cartilage. Proline (~3g per serving (15g)) is the structural amino acid chondrocytes use to synthesise new collagen matrix within the joint.
For athletes, the Baar protocol is worth noting: 15g of collagen-type protein consumed 60 minutes before mechanical loading (exercise) — combined with vitamin C — produces significantly greater collagen synthesis in tendons and ligaments than protein alone. Each scoop of reGrounded fits that protocol precisely.
Amino Acid | Per Serving (15g) | Primary Role
---|---|---
Glycine | ~5g | Sleep, inflammation, glutathione synthesis
Proline | ~3g | Collagen structure, wound repair, joint matrix
Hydroxyproline | ~2.5g | Collagen stability, fibroblast signalling
Glutamic Acid / Glutamine | ~2.25g | Gut lining fuel, immune function
Alanine | ~2.25g | Glucose metabolism, immune support
Arginine | ~2g | Nitric oxide, circulation, wound healing
Lysine | ~1g | Collagen cross-linking, calcium absorption
+ Hyaluronic Acid | 100mg | Skin hydration, joint lubrication
