Assessment · Section 1 of 5
Gut health & microbiome axis
The gut-brain axis is a bidirectional highway — vagus nerve, enteric nervous system, and gut-derived neurotransmitters (around 90% of your body's serotonin is produced down here). These questions probe for dysbiosis markers.
SPECIMEN 1.1 · BOWEL REGULARITY
How would you describe your bowel regularity?
Bristol Stool Scale correlates microbiome diversity with intestinal transit time. Irregular transit impairs absorption of tryptophan and other neurotransmitter precursors — with direct downstream effects on mood and cognition.
Daily, well-formed stools (Bristol type 3–4)
OPTIMAL TRANSIT
Variable — oscillates between loose and hard
MOTILITY DYSFUNCTION INDICATOR
Frequently irregular (3+ days off pattern)
ELEVATED DYSBIOSIS RISK
Chronic — mostly constipated or loose
LIKELY GUT-BRAIN AXIS DISRUPTION
SPECIMEN 1.2 · POST-PRANDIAL SYMPTOMS
Do you experience bloating, gas, or abdominal discomfort after meals?
Post-prandial symptoms can indicate SIBO, lactose/fructose malabsorption, or reduced digestive enzyme activity — each compromising nutrient availability for neurotransmitter synthesis.
NEVERALWAYS
SPECIMEN 1.3 · DIETARY DIVERSITY
How diverse is your diet in terms of plant variety per week?
The American Gut Project found that eating 30+ different plant foods per week is the single strongest predictor of microbiome diversity — more than any probiotic supplement tested.
30+ different plant foods per week
OPTIMAL MICROBIOME DIVERSITY THRESHOLD
15–29 varieties per week
MODERATE DIVERSITY
Fewer than 15 plant varieties per week
LOW DIVERSITY — DYSBIOSIS RISK
Mostly the same foods daily, low plant intake
HIGH DYSBIOSIS RISK
SPECIMEN 1.4 · FERMENTED FOODS
How often do you eat fermented or probiotic-rich foods?
A 2021 Stanford RCT found a high-fermented food diet increased microbiome diversity more effectively than high-fibre alone — and measurably reduced 19 inflammatory markers including IL-6.
Daily (yogurt, kefir, kimchi, sauerkraut, etc.)
A few times per week
Rarely — once a week or less
Almost never
Section 2 of 5
Cognitive performance & neuroplasticity
Assessing working memory, executive function, mental clarity, and BDNF (brain-derived neurotrophic factor) proxy markers — all of which are highly modifiable, and all of which correlate with lifestyle, sleep, and systemic inflammation levels.
SPECIMEN 2.1 · SUSTAINED ATTENTION
Rate your ability to focus on a demanding task for 90+ minutes without significant distraction.
Sustained attention reflects prefrontal cortex function, dopamine system integrity, and adenosine clearance efficiency during sleep. It's one of the first cognitive capacities to degrade under chronic stress.
VERY POOREXCELLENT
SPECIMEN 2.2 · NEUROINFLAMMATION PROXY
How often do you experience "brain fog" — mental cloudiness, slow thinking, or word-finding difficulties?
Brain fog is a clinical proxy for neuroinflammation, often driven by gut dysbiosis, elevated IL-6/TNF-α, or suboptimal thyroid and glucose regulation. It's a symptom, not a condition — which means the root cause is findable.
NEVERDAILY
SPECIMEN 2.3 · WORKING MEMORY
How would you describe your working memory in daily life?
Working memory — holding and manipulating information in real-time — reflects hippocampal integrity and BDNF availability. Both are highly responsive to sleep quality, aerobic exercise, and chronic stress load.
Sharp — I rarely lose the thread mid-task
Occasionally miss things, but mostly reliable
Frequently forget mid-task, lose train of thought
Significant issues — affects my work regularly
SPECIMEN 2.4 · COGNITIVE RESERVE
Do you engage in regular cognitively challenging activities?
Cognitive reserve — built through learning, complex problem-solving, and social engagement — is the strongest known protective factor against age-related cognitive decline (Stern, 2009). You can literally grow your brain's resilience.
Yes — learning, complex work, or creative pursuits daily
Sometimes — a few times per week
Rarely — mostly routine or passive tasks
Almost never — highly repetitive daily pattern
Section 3 of 5
Stress & HPA axis regulation
The hypothalamic-pituitary-adrenal axis governs cortisol rhythmicity. Chronic HPA activation suppresses hippocampal neurogenesis, impairs gut barrier integrity ("leaky gut"), and elevates neuroinflammatory markers. It's the system that connects stress to almost everything else.
SPECIMEN 3.1 · PERCEIVED STRESS LOAD
How would you rate your overall perceived stress level over the past 30 days?
Adapted from Cohen's Perceived Stress Scale — the most validated self-report measure of psychological stress and its physiological downstream effects on the body's regulatory systems.
VERY LOWOVERWHELMING
SPECIMEN 3.2 · VAGAL TONE & REGULATION
Do you have reliable strategies for emotional regulation — breathwork, mindfulness, exercise, therapy?
Vagal tone — measurable via heart rate variability — is enhanced by consistent parasympathetic activation. This directly modulates gut motility, immune function, and the cortisol response. Think of it as your body's own anti-inflammatory dial.
Yes — consistent practice, works well for me
I have strategies but use them inconsistently
Rarely use any intentional strategies
No strategies — I feel overwhelmed often
SPECIMEN 3.3 · ALLOSTATIC LOAD MARKERS
How often do you experience physical tension symptoms — headaches, tight jaw, shoulder pain, gut cramps?
These are somatic markers of allostatic load — the cumulative physiological cost of chronic stress. Allostatic overload precedes burnout and measurably accelerates cognitive aging. Your body is keeping score.
RARELYCONSTANTLY
SPECIMEN 3.4 · CORTISOL AWAKENING RESPONSE
How do you feel when you wake up in the morning?
The cortisol awakening response (CAR) — a sharp spike within 30 minutes of waking — is a reliable biomarker of HPA axis function. Consistently low morning energy suggests a blunted CAR, or subclinical burnout progressing beneath the surface.
Alert and energised — genuinely ready to go
Okay — takes about 30–60 min to feel normal
Sluggish and dreading the day most mornings
Exhausted even after a full night — chronic fatigue pattern
Section 4 of 5
Sleep architecture & glymphatic function
Sleep is when the brain's glymphatic system activates to clear metabolic waste — including amyloid-β and tau proteins. Even a single night of poor sleep measurably increases Alzheimer's-associated markers. Sleep also drives gut microbiome circadian rhythmicity.
SPECIMEN 4.1 · SLEEP DURATION
How many hours of sleep do you average per night?
Extensive meta-analyses confirm 7–9 hours as the human optimal. Sub-7hr sleep impairs hippocampal memory consolidation, elevates baseline cortisol, and suppresses immune surveillance. There's no such thing as adapting to less.
7–9 hours consistently
6–7 hours most nights
5–6 hours — chronically short
Under 5 hours or highly irregular
SPECIMEN 4.2 · SLEEP QUALITY
Rate your sleep quality — how restorative does it feel?
Sleep quality (slow-wave and REM architecture) matters as much as duration. Poor deep sleep = impaired glymphatic clearance and suppressed BDNF release the following day. Duration without architecture is just lying still.
VERY POOREXCELLENT
SPECIMEN 4.3 · CIRCADIAN CONSISTENCY
Do you have consistent sleep and wake times — within 30 minutes of each other daily?
"Social jetlag" — irregular schedules even without travel — dysregulates cortisol, melatonin, and gut microbiome rhythmicity. Your circadian clock governs gene expression in nearly every organ. Consistency is free medicine.
Yes — very consistent, 7 days a week
Mostly — weekdays regular, weekends drift slightly
Irregular — shifts 2+ hours regularly
No regular pattern — highly variable
SPECIMEN 4.4 · PRE-SLEEP LIGHT EXPOSURE
How often do you use screens in the hour before bed?
Blue light suppresses melatonin production by up to 50% (Harvard, 2015). This delays sleep onset and compresses slow-wave sleep — the stage most critical for waste clearance and memory consolidation.
NEVEREVERY NIGHT
Section 5 of 5
Metabolic health & neuroinflammation drivers
Insulin resistance, oxidative stress, chronic inflammation, and sedentary behaviour are the four main modifiable drivers of accelerated brain aging. This section maps your metabolic risk profile.
SPECIMEN 5.1 · BDNF-STIMULATING EXERCISE
How much aerobic or resistance exercise do you get per week?
Exercise is the most potent BDNF stimulant known to science. 150 min/week moderate aerobic activity produces measurable hippocampal volume increase (Erickson et al., 2011). It also directly reduces IL-6, TNF-α, and neuroinflammatory load.
150+ min/week aerobic + 2x strength training
90–150 min/week — mostly one type
Under 90 min/week, inconsistent
Mostly sedentary — minimal movement
SPECIMEN 5.2 · GLYCAEMIC & INFLAMMATORY LOAD
How would you describe your sugar and ultra-processed food intake?
High glycaemic load diets drive neuroinflammation through AGE (advanced glycation end-products) formation and promote gut dysbiosis by feeding pathogenic species. Firmicutes over Bacteroidetes — and your brain pays the price.
Mostly whole foods — minimal sugar and UPFs
Balanced — some UPFs but mostly real food
Regular UPF/sugar consumption most days
High sugar/UPF diet — a large part of daily eating
SPECIMEN 5.3 · CEREBRAL HYDRATION
How is your daily hydration?
Even 1–2% dehydration impairs working memory and sustained attention (Adan, 2012). The brain is ~75% water; dehydration reduces cerebral blood flow and amplifies cortisol reactivity — a subtle but consistent drag on performance.
8+ glasses of water daily, consistently
About 5–7 glasses — fairly consistent
3–5 glasses — often forget
Under 3 glasses — rarely drink plain water
SPECIMEN 5.4 · SOCIAL COGNITION & PURPOSE
How would you rate your social connection and sense of purpose?
Social isolation increases dementia risk by 26% (Holt-Lunstad meta-analysis). Purpose and social engagement are independent predictors of cognitive longevity — operating through reduced cortisol and oxytocin-mediated neurogenesis. Connection is neuroprotective.
ISOLATED / ADRIFTDEEPLY CONNECTED
NatureKing Health · Assessment Complete
Your Brain & Gut Vitality Profile
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out of 100
Brain Vitality Index™
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Key findings
Priority recommendations