Nature Communications | Dylan Chiang

Paper reading: Capsaicin diet drives gut inflammation and exosomal miR-17-3p elevation in idiopathic short stature

Sun, 18 Jan 2026 00:00:00 +0000

#paper information

Title: Capsaicin diet drives gut inflammation and exosomal miR-17-3p elevation in idiopathic short stature Journal: Nature Communications Year: 2025 Date: 2025-12-30

Research background

Idiopathic Short Stature (ISS) refers to a condition in which the height is two standard deviations lower than the person of the same age, but growth hormone (GH) levels are normal and there is no obvious pathological cause. The cause of ISS has long been a mystery.

Although genetics is the main factor in determining height, the influence of environmental factors such as diet cannot be ignored. Past research has mostly focused on nutritional deficiencies (such as calcium, protein), but how specific dietary components affect bone growth through molecular mechanisms is still poorly understood. This study focuses on capsaicin, the main component of spicy food, and explores whether and how it affects children’s growth and development.

Research methods

The research team adopted a systematic approach from clinical correlation analysis to molecular mechanism verification:

Clinical correlation analysis: Analyze the relationship between children’s eating habits and height, especially the intake of capsaicin.
Animal model: Establish a rat model of long-term ingestion of capsaicin and observe its effects on body length, femur length and growth plate structure.
Exosome tracking: Isolate exosomes (Exosomes) in serum, analyze their miRNA content, and track whether these exosomes can reach the bone growth plate.
Molecular mechanism exploration: Verify the regulatory effect of candidate miRNA on growth signaling pathways (such as ZNF148/SOS1/RAS/ERK and PI3K/AKT) in chondrocytes cultured in vitro.

Main findings

1. Capsaicin intake causes growth retardation and intestinal inflammation

In animal experiments, rats that long-term consumed a diet rich in capsaicin had significantly lower body weight and length than those in the control group. Histological examination found that these rats had thinner growth plates** and reduced new bone formation. At the same time, these rats showed significant intestinal inflammation. Notably, their growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels were normal, fully consistent with the clinical features of ISS.

2. Exosomal miR-17-3p is a key messenger

The study found that capsaicin-induced intestinal inflammation led to a significant increase in the levels of miR-17-3p carried by exosomes in the serum. These exosomes act as “long-range messengers” and are transported from the intestine to the growth plate cartilage of the bone.

3. Molecular mechanism: inhibiting chondrocyte proliferation

After reaching the growth plate, miR-17-3p enters chondrocytes, targeting and inhibiting the expression of the ZNF148 gene. Downregulation of ZNF148 further blocked SOS1 and the downstream RAS/ERK and PI3K/AKT signaling pathways. These pathways are critical for chondrocyte proliferation and hypertrophy, key processes in longitudinal bone growth. Therefore, inhibition of this pathway directly results in stunted bone growth.

Research significance

1. Revealed the new mechanism of the “gut-bone axis”

This study established a specific “diet-intestinal inflammation-exosomes-bone growth” cross-organ regulation model, proving that intestinal microorganisms and inflammatory status can directly affect the development of distal organs (bones) through non-hormonal pathways (exosomal miRNAs).

2. Provides a new etiological explanation for ISS

For many short children with normal growth hormone levels, this study offers a possible explanation: Perhaps it’s not a lack of hormones, but chronic inflammatory signals triggered by specific dietary habits that inhibit the bone’s response to growth.

3. Potential therapeutic targets

The findings suggest that, in addition to growth hormone therapy, intervention targeting miR-17-3p (such as the use of antisense oligonucleotides) or improving intestinal inflammation may become a new strategy for the treatment of some children with ISS. Of course, the simplest advice may be this: Avoid excessive consumption of spicy foods in developing children.

My understanding

1. Molecular-level interpretation of “You are what you eat”

This statement is usually understood to mean that nutrients make up body tissues. But the study shows a deeper meaning: Food is not just fuel, it’s a signal. Capsaicin itself is not a component of bone, but the biological response it triggers (inflammation -> release of exosomes) is like an “instruction” that rewrites the growth program of bone cells.

2. Growth hormone is not a panacea

When encountering children with ISS clinically, parents often anxiously seek growth hormone injections. However, if the cause is that the downstream cell signaling pathway is “stuck” by inflammatory factors (such as miR-17-3p), simply increasing the upstream growth hormone may have limited effect. This reminds us that medicine needs to shift from “replenishing deficiency” to “relieving inhibition.”

3. The collision of traditional wisdom and modern science

There is a saying in many cultures that “children who eat too much spicy food will not grow taller” (although it is more about eating spicy food that will “get angry” or affect digestion). This study unexpectedly provides rigorous molecular biology evidence for this folk observation. It reminds us that in developmental biology, gut health and systemic immune status may be more critical than we thought.

(Note: Please search for the paper published by Wang et al. in the December 2025 issue)

Reading date: 2026-01-18 Notes organized: Dylan Chiang

Paper reading: How people think about being alone shapes their experience of loneliness

Sun, 04 Jan 2026 00:00:00 +0000

#paper information

Title: How people think about being alone shapes their experience of loneliness Journal: Nature Communications Year: 2025 DOI:

Research background

Loneliness is widely regarded as a global health challenge, closely related to depression, cardiovascular disease and even premature death. In response to this crisis, media and public health campaigns have sprung up in various countries to warn the public about the dangers of social isolation.

However, this study raises a paradoxical point of view: **Do these well-intentioned propaganda actually exacerbate people’s loneliness because they overemphasize the negative consequences of “being alone”? **

The core theory is that “being alone” (objective state) and “loneliness” (subjective feeling) are completely different. The research team hypothesized that people’s weighing beliefs (Beliefs) about being alone are the key to determining whether being alone causes pain or recovery.

Research methods

This study constructed a complete chain of arguments through 5 complementary experiments and surveys (total sample size N = 3,547):

Media Discourse Analysis (Study 1): Analyze the top ten newspapers in the United States from 2020 to 2022 to quantify their tendency to depict solitude.
Cause and Effect Experiment (Study 2): Randomly assign participants to read reports about the “benefits” or “risks” of being alone, and observe real-time changes in beliefs.
Experience Sampling (Study 3): 161 young people were tracked five times a day for two weeks to capture solitary behavior and psychological changes in daily life.
Cross-cultural verification (Study 4 & 5): Across 9 countries on six continents, verify whether this psychological mechanism is universal.

Main findings

1. The media’s “high stigma” against solitude

The study found that U.S. news headlines were 10 times more likely to describe solitude as “harmful” than as “beneficial.” In the main text, risks are mentioned 5 times more frequently than benefits are mentioned. The mass media almost equates “being alone” with “danger.”

2. The causal impact of beliefs on loneliness

Experiments have shown that even brief exposure to information about the benefits of solitude can significantly improve people’s beliefs about solitude. And this belief directly determines subsequent behavioral responses.

3. The “buffering and catalyzing” effect in daily life

This is the best part of the study (Study 3):

Negative Belief Holder: The longer you spend alone, the more intense your loneliness will rise. To them, being alone is a threat from which they need to escape.
Positive Belief Holders: After being alone, loneliness is significantly reduced. They see solitude as an opportunity to “recharge” and “repair themselves.”
Generalizability: This effect has been proven across different cultures, including collectivistic and individualistic cultures.

Research significance and inspiration

1. The “echo effect” of public health propaganda

The study raises a red flag for public health experts: campaigns that emphasize only the dangers of loneliness (such as “Loneliness is equivalent to smoking 15 cigarettes a day”) may inadvertently reinforce the public’s fear of being alone. When people have to be alone, which is almost inevitable in modern life, this fear translates into deeper psychological distress.

2. New approaches to cognitive intervention

Rather than forcing everyone to socialize, help those who feel lonely re-examine the value of being alone. Cultivating positive beliefs about being alone may be more effective in alleviating subjective loneliness than increasing social interaction.

My understanding

This paper provides a very insightful perspective: **Part of the reason why we feel lonely is because we are told that “being alone is not normal.” **

1. The self-fulfilling prophecy of cognitive frameworks

From the perspective of cognitive evaluation theory, being alone is a neutral stimulus. If we assume that being alone represents a social failure or a health threat (negative beliefs), then when we are alone, the brain will activate the threat detection mechanism, producing feelings of anxiety and loneliness. This creates a vicious cycle: the more lonely you feel, the more you fear being alone; the more you fear being alone, the more painful it is when you are alone.

2. Media Ecology and Mental Toughness

In the current era of digital media, social media constantly showcases the lively scenes of others, while traditional media constantly warns of the dangers of isolation. This double attack has greatly compressed our psychological space to face ourselves calmly. This study reminds us that building cognitive resilience (Belief Resilience) to “the benefits of being alone” may be an essential skill for modern people.

3. A “moderate turn” in policy

Public health policies should shift from simply “anti-loneliness” to “supporting healthy solitude.” Propaganda should include how to spend quality time alone and how to use alone time for creative thinking or emotional regulation, rather than just treating it as a defective product after a lack of social interaction.

4. Conclusion: Solitude is a kind of self-healing ability

Loneliness is not caused by spatial walls, but by psychological frameworks. Perhaps the biggest lesson from this research is that in an age where everyone is connected, being able to enjoy alone time is an important form of mental toughness.

It means that you no longer passively endure loneliness, but actively use this time to carry out self-repair (Rejuvenation) and recharge. When being alone is no longer a threat, but an opportunity, you have a powerful anti-loneliness mechanism.

Reading date: 2026-01-04 Notes organized: Dylan Chiang

Paper reading: Topological turning points across the human lifespan

Sun, 04 Jan 2026 00:00:00 +0000

#paper information

Title: Topological turning points across the human lifespan Journal: Nature Communications Year: 2025 DOI:

Research background

The structural topology of the human brain develops nonlinearly with age and is closely related to cognitive trajectories. Past research has tended to focus on specific age ranges (such as childhood or old age) but lacks a global perspective across the entire life cycle.

This study raises a core question: ** Are there key “turning points” in brain organization that mark the brain entering different stages of development? **

To answer this question, the research team collected nine data sets ranging in age from 0 to 90 years, with a total sample size of 4,216 people.

Research methods

1. Data analysis scale

Number of samples: N = 4,216 (neurotypical subset n = 3,802)
Technology: Diffusion Imaging
Metrics: 12 Graph Theory Metrics, used to quantify brain tissue architecture.

2. Manifold Learning

Use UMAP (Uniform Manifold Approximation and Projection) to project high-dimensional topological data into a three-dimensional manifold space.
The aim is to capture the non-linear dynamics of age-related changes in brain topology.

Key findings: Five life stages and four turning points

The study found that there are four major “turning points” in the development of brain topology, which occur around the ages of 9, 32, 66 and 83 years old. These turning points divide life into five unique Epochs:

Stage	Age range	Name	Characteristic description
Epoch 1	0–9 years old	Infancy to childhood	Global integration decreases and local preference (Segregation) increases.
Epoch 2	9–32 years old	Adolescence	The degree of brain network integration increases, and the small-world property (Small-worldness) is significantly improved.
Epoch 3	Ages 32–66	Adulthood	Developmental trajectories stabilize, with a slow decline in integration and an increase in local efficiency.
Epoch 4	Age 66–83	Early aging	Changes in modularity become the dominant feature.
Epoch 5	83–90 years old	Late aging	The relationship between age and topology weakens, and subgraph centrality becomes the main feature.

Detailed description of key findings

32: The most powerful turning point in your life
- Research shows that age 32 is the most dramatic time for brain topological rewiring.
- This is consistent with the finding that White Matter Volume and Fractional Anisotropy peak around age 29.
- This marks the brain’s shift from the “increased efficiency and integration” stage to the “increased isolation and stability” stage.
Age 9: The End of Childhood -The turning point coincides with the onset of puberty, peak cortical thickness, and substantial improvements in cognitive abilities.
- Marks a structural shift in brain structure from a single pattern of growth to a more complex pattern of maturation.
Ageing does not proceed at a uniform speed
- The turning point between ages 66 and 83 heralds the onset of a “simplified” mode of the brain, which is associated with an accelerated decline in white matter integrity and an increased risk of health problems such as dementia and high blood pressure.

Research significance and inspiration

1. Redefine “adolescence”

The study found that topological developmental trajectories during adolescence continue until age 32, well beyond what is traditionally thought to be around age 20. This supports the modern neuroscientific view that the brain matures much later than we thought.

2. The guiding value of non-linear development

The development of the brain does not rise in a straight line and then decline, but is a “turn” full of qualitative changes. This has important implications for clinical diagnosis, helping to distinguish normal staged changes from pathological cognitive decline.

My understanding

This study uses large-scale data to demonstrate the nonlinear dynamics of human brain structural topology during the life cycle, the most noteworthy of which is the turning point of 32 years old. Examined from the perspective of phylogeny and developmental biology, this finding provides several profound implications:

1. Trade-off between structure and function

Before the age of 30, the main axis of brain development is “increased integration.” This is a structured support period for extensive exploration and learning of the external environment. The brain improves the efficiency of information exchange throughout the brain by strengthening long-distance connections. However, this high level of integration is also accompanied by higher energy consumption and signal interference.

The turning point at age 32 marks the brain’s shift from “comprehensive expansion” to “precision optimization.” The decline in overall integration is not equivalent to a decline in functionality, but more like a structural “specialization.” Specific modules (Sub-networks) become more independent. This enhancement in modularity is beneficial to the stability of performing specific tasks and reduces noise interference in irrelevant areas. In cognitive psychology, this corresponds to the transition from “divergent flexibility” to “professional proficiency.”

2. Synergy of biological markers

The age of 32 does not exist in isolation. It is highly synchronized with peak white matter integrity, completion of the myelination process, and stabilization of neurotransmitter systems. This shows that during the course of evolution, the human body has set a biological clock that closes the “extensive remodeling window” at the beginning of the fourth decade. This synchronicity implies that the brain structure is shifted to better adapt to the long-term social division of labor and survival challenges in adulthood, and to invest limited metabolic resources into more productive specialized modules.

3. Reconstruction of the definition of “adolescence”

If the activity of topological rewiring is considered an indicator of adolescence, this study clearly shows that our definition of brain maturity (often pegged at around age 20) may be too dependent on legal and cultural labels rather than biological facts. From a brain structure perspective, the aftermath of adolescence actually extends into age 32. During this period, the brain still has strong potential for global integration, which explains why this period is the visual window for the final consolidation of professional skills shaping and worldview.

4. Precursors and nonlinear characteristics of aging

The study’s description of the turning points at ages 66 and 83 reveals that aging is not a slow wear-and-tear process but a staged evolution involving specific topological features. Especially after the age of 80, the relationship between age and topology weakens, suggesting that individual differences (such as genes, lifestyle, reserve capacity) may exceed the influence of basic developmental laws at extremely advanced ages.

In summary, this study reminds us that the brain executes different optimization logics at different stages of life: when young, it pursues “connecting everything” to gain possibilities, in middle age, it pursues “module independence” to ensure efficiency, and in old age, it tries to maintain core connections to cope with inevitable hardware degradation. This structural shift is not a negative degeneration, but a manifestation of life’s constant search for optimal adaptive solutions as time goes by.

Reading date: 2026-01-04 Notes organized: Dylan Chiang

Nature Communications | Dylan Chiang

Paper reading: Capsaicin diet drives gut inflammation and exosomal miR-17-3p elevation in idiopathic short stature

Research background

Research methods

Main findings

1. Capsaicin intake causes growth retardation and intestinal inflammation

2. Exosomal miR-17-3p is a key messenger

3. Molecular mechanism: inhibiting chondrocyte proliferation

Research significance

1. Revealed the new mechanism of the “gut-bone axis”

2. Provides a new etiological explanation for ISS

3. Potential therapeutic targets

My understanding

1. Molecular-level interpretation of “You are what you eat”

2. Growth hormone is not a panacea

3. The collision of traditional wisdom and modern science

Related resources

Paper reading: How people think about being alone shapes their experience of loneliness

Research background

Research methods

Main findings

1. The media’s “high stigma” against solitude

2. The causal impact of beliefs on loneliness

3. The “buffering and catalyzing” effect in daily life

Research significance and inspiration

1. The “echo effect” of public health propaganda

2. New approaches to cognitive intervention

My understanding

1. The self-fulfilling prophecy of cognitive frameworks

2. Media Ecology and Mental Toughness

3. A “moderate turn” in policy

4. Conclusion: Solitude is a kind of self-healing ability

Related resources

Paper reading: Topological turning points across the human lifespan

Research background

Research methods

1. Data analysis scale

2. Manifold Learning

Key findings: Five life stages and four turning points

Detailed description of key findings

Research significance and inspiration

1. Redefine “adolescence”

2. The guiding value of non-linear development

My understanding

1. Trade-off between structure and function

2. Synergy of biological markers

3. Reconstruction of the definition of “adolescence”

4. Precursors and nonlinear characteristics of aging

Related resources