Gut microbiome, Spleen Dampness and dysbiosis: a TCM-Science convergence

Ten years after the microbiome revolution, one fact stands firm: the gut microbiome is a central actor in metabolism and obesity. Individuals with obesity have a microbiome that differs significantly from that of lean individuals. This is not merely a consequence of obesity - it is also a cause. And the idea that the gut is the seat of a profound transformation conditioning everything else in metabolism is one that traditional Chinese medicine had integrated two millennia ago, under the concept of the Spleen-Stomach.

What the microbiome does to metabolism

The obesity microbiome: a distinct profile

The pioneering work of Jeffrey Gordon (Ley et al., 2006, Nature) demonstrated that individuals with obesity display a distinct microbial composition: an increased Firmicutes/Bacteroidetes ratio, reduced bacterial diversity, and enrichment in pro-inflammatory bacteria (notably lipopolysaccharide-producing species).

These gram-negative bacteria release lipopolysaccharides (LPS) into the bloodstream - a phenomenon termed metabolic endotoxaemia. LPS bind to TLR4 (Toll-like receptor 4) receptors and activate NF-kB, triggering systemic chronic inflammation that promotes insulin resistance and fat storage (Cani et al., 2008, Diabetes).

The microbiome produces short-chain fatty acids

Beneficial bacteria (Bifidobacterium, Lactobacillus, Akkermansia muciniphila, Faecalibacterium prausnitzii) ferment prebiotic fibres and produce short-chain fatty acids (SCFAs) - butyrate, propionate, acetate. These molecules:

• Nourish colonocytes and reinforce the intestinal barrier (butyrate)
• Improve insulin sensitivity at the hepatic and muscular level (propionate)
• Activate GLP-1 secretion (satiety hormone) by enteroendocrine L cells
• Reduce inflammation by inhibiting NF-kB and stimulating regulatory T cells

Intestinal permeability: the leaking wall

The healthy gut is equipped with a tight epithelial barrier, maintained by tight junction proteins (zonulin, occludin, claudins). In metabolic syndrome, this barrier becomes permeable: LPS, bacterial fragments and dietary antigens pass into circulation and sustain systemic inflammation.

The Spleen and intestine in TCM: the pivot of transformation

The Spleen governs transport in the intestines

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The Spleen and Stomach are the granaries of grains and water-grains. The five organs extract their essence from this granary. What remains is the untransformed Dampness.

」

In TCM, the Spleen (Pi 脾) governs not only the transformation of foods but also the transport (Yun 运) of fluids and nutrients throughout the organism. The Small Intestine (Xiao Chang 小肠) ‘separates the pure from the turbid’: pure nutrients ascend to the Spleen, while waste descends to the Large Intestine.

When the Spleen is weak, this transport is disrupted: ‘turbid’ substances remain in the intestine and generate pathological Dampness there. Bloating, irregular stools, flatulence, post-meal fatigue - all of this corresponds in TCM to a Spleen Deficiency with Dampness stagnation in the intestine.

The correspondence with dysbiosis

Pro-inflammatory dysbiosis (excessive pathological fermentation, increased intestinal permeability) corresponds remarkably to what TCM describes as Dampness stagnating in the Middle and Lower Burners. Excessive intestinal fermentation is literally ‘fermentation’ - a process of heat and decomposition that, in TCM, corresponds to the generation of Dampness-Heat from stagnant Dampness.

Aliment	Nature	Saveur	Méridiens	Actions	Précautions
Diverse and balanced microbiome	Neutral	Strong Spleen - transport of pure and turbid well ordered	Varied fibres, fermented foods, minimal refined sugars
Dysbiosis - elevated Firmicutes/Bact. ratio	Cold	Spleen Dampness - transformation disrupted	Diverse prebiotics, eliminate refined sugars
Metabolic endotoxaemia (elevated LPS)	Warm	Toxic Dampness-Heat in the Blood	Intermittent fasting, pomegranate, anti-LPS polyphenols
Increased intestinal permeability	Cold	Spleen Qi Deficiency - Middle Burner wall failing	Glutamine, zinc, vitamin D, collagen (bone broth)
SCFA deficit (butyrate)	Neutral	Large Intestine Qi Deficiency	Resistant fibres, clarified butter (ghee), pulses
Reduction in Akkermansia muciniphila	Cool	Weakening of the protective mucus layer	Polyphenols (pomegranate, blueberries), standardised extract

Nutritional strategy for the microbiome according to TCM

Nourishing beneficial bacteria: prebiotics

Prebiotic fibres are the food of beneficial bacteria. In TCM, they correspond to foods that nourish Yin and gently drain Dampness:

• Inulin and FOS (garlic, onion, leek, Jerusalem artichoke, chicory): classic prebiotics, nourish Bifidobacterium
• Resistant starch (cooled rice, cold potato, green banana, pulses): produces butyrate
• Beta-glucans (oats, barley, Job’s tears Yi Yi Ren): drain Dampness and nourish Akkermansia
• Pectin (apple with skin, quince, citrus): protective gel for the intestinal mucosa

Reintroducing beneficial bacteria: dietary probiotics

Fermented foods directly introduce live bacteria. In TCM, fermented foods (Fa Jiao 发酵) harmonise the Spleen and tonify Yin:

• Miso (Mi Su 味噌): sweet and salty nature, Spleen affinity, contains Lactobacillus, improves postprandial glycaemia
• Tempeh: soy fermentation, rich in probiotics and complete protein, neutral nature
• Sauerkraut and kimchi: abundant Lactobacillus, prebiotic fibres, drain Dampness
• Milk or coconut kefir: diverse probiotic strains - to moderate in Profile C if Dampness-Heat is present

Reinforcing the intestinal barrier

• Glutamine: the principal amino acid of enterocytes, may be supplemented at 5-10 g/day to restore tight junctions
• Zinc carnosine: reinforces the intestinal mucosa
• Bone broth: collagen, glycine, proline - in TCM, tonifies Spleen and Stomach Yang, restores the mucosa
• Vitamin D: VDR receptors on tight junction genes - target 50-70 ng/mL

FAQ

Are capsule probiotics as effective as fermented foods?

Both have their merits. Fermented foods provide a diversity of strains and a beneficial food matrix; supplements allow high doses of specific strains. In practice, begin with daily fermented foods (miso, sauerkraut, kefir) and consider a course of concentrated probiotics (10-50 billion CFU, Lactobacillus + Bifidobacterium strains) as a 4 to 8-week course if needed.

Is intestinal permeability reversible?

Yes, provided the approach is correctly conducted. Within 4 to 8 weeks of suppressing aggravating factors (alcohol, refined sugars, non-steroidal anti-inflammatory drugs) and introducing restorative nutrients (glutamine, zinc, vitamin D, bone broth), a significant improvement in the intestinal barrier is documented.

Can the microbiome of someone with obesity genuinely change?

Yes, and relatively rapidly. Microbiome composition can change significantly within 1 to 4 weeks of dietary change (David et al., 2014, Nature). The persistence of change depends on the durability of new dietary habits. A diverse microbiome, rich in butyrate producers, can be established within 12 weeks of a Mediterranean diet or eating in accordance with Chinese dietary therapy principles.

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