Cyclic microbial competition may drive recurring skin damage through protease release
In reconstructed skin at equal drug exposure within tissue, competition among antimicrobial-producing, resistant and sensitive microbes could drive protease-linked damage cycles. Absent cyclic advantages in pairwise competition, or persistent damage cycles in a sterile model, would reject this as a sufficient explanation.
Stage of verification
- Hypothesis published2026-09-25
- Indirect evidenceAssessed at 4 of 10
- Direct testAwaited
Map of the hypothesis
Hover over an icon or tap it to see its name.
Where in the body
Ageing mechanism
Kind of knowledge gap
A double ring marks the main placement where a group contains several values.
Target map
Every target of every published hypothesis, each with the actions a hypothesis can propose on it. The targets and the actions of this hypothesis are drawn solid.
Microbial community
Gut microbiota
The community of microorganisms living in the gut
Where this hypothesis actsSkin exposed to repeated applications of a drug or its vehicle, with three competing microbial strategies
Hypotheses on this target 3
Population balance1
Community restoration
Colonisation1
What is proposed
Population balance
Remove one participant to interrupt cyclic microbial competition
With whatNot stated in the record
HowRemove one member of the community comprising an antimicrobial producer, a resistant strain and a sensitive fast-growing strain
Possible result
Possible interruption of repeated protease and skin damage peaks
From the recordУдаление одного участника разрывает последовательность повторных пиков, а восстановление трехкомпонентного сообщества возвращает ее.
Enzyme
Proteases
Enzymes that break down proteins
Where this hypothesis actsProtease secreted by a skin-damaging strain within the competing microbial community
Hypotheses on this target 7
Inhibition6
Activation
Lower level1
Higher level
Replacement
Protection from degradation
Cofactor removal
Synthesis suppression
Function preservation
What is proposed
Inhibition
Disable the damaging strain's protease
With whatMicrobial intervention
HowReplace the damaging strain with a variant whose protease is switched off, preserving microbial competition
Possible result
Possible elimination of skin damage while microbial competition persists
From the recordЗамена повреждающего штамма вариантом с выключенной протеазой сохраняет микробную конкуренцию, но устраняет повреждение кожи.
All targets of the lab
Every target read from the published hypotheses, each kind around its pictogram. A larger mark means more hypotheses act on that target. Point at a mark and the actions proposed on it branch out of it.
Solid and named: the targets of this hypothesis
Explore in depth
The logic
The train of thought that ends in this hypothesis. Each stage is the reason the next exists. The master question narrows to a goal, the goal to an unknown nobody has closed, the unknown to the hypothesis proposed here. Every step below says what it rests on and what carries it.
Keeping restored skin healthy may depend on what repeated treatment does to the microbes living on its surface. The unexpected move is to propose that three competing microbial types repeatedly replace one another, with one releasing an enzyme that damages skin. This is a proposal generated by the pipeline, not a measured explanation of recurring skin damage.
- Repeated drug or carrier applications change the competitive advantages of three microbial types.
- The producer suppresses the sensitive type through its microbe-inhibiting substance.
- The resistant type outcompetes the producer by avoiding the cost of making that substance.
- The sensitive type outcompetes the resistant type by avoiding the cost of resistance.
- Under competition conditions that sustain repeated changes in dominance, the enzyme-producing type repeatedly increases and decreases.
- Changes in its abundance and enzyme release create proposed waves of skin damage followed by recovery.
- Damage and recovery change drug delivery, while continued microbial competition could keep the damage cycle going despite maintained tissue drug levels.
It resembles a three-player game in which each player can beat one opponent but loses to the other, so no player has an advantage over everyone.
Where the picture breaks: Those rules alone do not guarantee repeated changes in who dominates. Living microbes also vary in total number and enzyme output, and the game says nothing about whether skin is damaged.
- Master questionstep 01 of 04
A treatment is sought that would restore the functioning of middle-aged human skin to that of young people.
Rests on: The supplied goal sets youthful skin function as the intended treatment outcome.
Stated in the chain - Goal pillarstep 02 of 04
The treatment objective is complete and lasting restoration of skin functions.
Rests on: The master question seeks restoration to youthful function; this stage makes completeness and durability explicit treatment goals.
Stated in the chain - Gap questionstep 03 of 04
A restored skin barrier, the outer layer that limits passage into and out of skin, might admit less maintenance drug. More frequent applications might then alternate insufficient treatment with damage, raising the question of whether adjusting applications to measured drug levels inside the tissue would stop the cycle at the same total dose.
Rests on: Lasting restoration requires understanding why treatment might alternate between repair and damage.
LeapThe preceding stages supply no maintenance drug, evidence that restored skin reduces its delivery, or basis for the proposed alternation between insufficient treatment and damage. These are newly introduced possibilities.
- Hypothesisstep 04 of 04
Repeated applications of a drug or its carrier, the material that delivers it, are proposed to change which skin microbes grow most successfully. A producer of a microbe-inhibiting substance defeats a sensitive competitor; a resistant competitor defeats the producer by avoiding production costs; and the sensitive competitor defeats the resistant one by avoiding resistance costs. If one competitor releases a damaging protease, their changing proportions could produce recurring injury and repair even when drug levels inside the tissue are maintained.S1
Rests on: The gap question introduces recurring damage during repeated treatment. A 2017 paper in Journal of Theoretical Biology describes models containing the proposed circular competitive advantages, but does not establish their operation in skin or their connection to proteases, tissue damage, repeated applications, or drug delivery.
Supported by literature
What is carried, and what is not. One screened source speaks to the three competitive relationships: the 2017 Journal of Theoretical Biology paper describes their cost-based logic in microbial models, without establishing skin damage or treatment effects. No supplied source establishes the full sequence from repeated applications through changing microbial dominance to recurring injury and altered drug delivery.
Where the reasoning is carried by something unstated · 1
- Gap question. The preceding stages supply no maintenance drug, evidence that restored skin reduces its delivery, or basis for the proposed alternation between insufficient treatment and damage. These are newly introduced possibilities. Establish the missing link before relying on this step.
How a result here could mislead · 3
- A rising proportion of the enzyme-producing type could be mistaken for rising damaging enzyme output. Its proportion can rise while its absolute number falls, and enzyme release per cell can also change. What closes it: Measure absolute numbers of living microbes alongside their proportions and active enzyme output over time. The proposal includes absolute counting and measured secretion per cell; those measurements must establish the damaging load rather than infer it from proportions alone.
- Disappearance of damage after removing one competitor could be credited to breaking circular competition when removal simply reduced the number of enzyme-producing cells. Disabling the enzyme could also change the altered strain's competitive performance; a strain is a distinct variant of a microbe. What closes it: Track competitor numbers and competitive relationships after removal and restoration of the three-member community. Confirm that the enzyme-disabled variant preserves the competition pattern while eliminating damage, as the prediction requires.
- Matching average drug levels could be mistaken for matching the drug concentration throughout the experiment. Remaining fluctuations, changes in the carrier's surface chemistry, or synchronized replacement of skin cells could then be credited to microbial competition. What closes it: Define and verify matched tissue exposure, the drug concentration over time inside the tissue. Keep application and carrier conditions comparable, include the proposed microbe-free comparison, and measure the carrier changes or timing of cell replacement needed to distinguish the named rival explanations.
What would make this wrong. The proposal identifies two observations that would defeat it as a sufficient explanation: failure to find the required circular advantages in competitions between pairs of the selected microbes, or persistence of the damage cycle in an otherwise matched microbe-free skin model. Its enzyme-mediated explanation would also fail if disabling the proposed damaging protease left the damage cycle intact while preserving microbial competition and matched drug exposure.
What it would change. If the proposed mechanism held, lasting restoration of skin function would require controlling the microbial competition that sustains damage; maintaining drug levels alone would not resolve that cause. The proposed tests concern reconstructed epidermis, a laboratory model of the skin's outer cellular layer. Success there would still not establish that the required competitors occur together in middle-aged human skin, that controlling them is safe and durable, or that doing so restores the full range of youthful skin functions.
Sources read · 1
Analysis of stability to cheaters in models of antibiotic degrading microbial communities. · Journal of theoretical biology · 2017
“Since producing of an antibiotic and being resistant to it are both costly, the resistant strain wins over the producer, similarly the sensitive wins over the resistant, and the producer can take over the sensitive population. This ’rock-paper-scissors’ interaction”
Does not settle: Источник не устанавливает связь такого цикла с кожей, протеазами, повреждением или восстановлением ткани, повторными нанесениями препарата либо его носителя, доставкой препарата или стабилизацией SPV_9.
The gap this hypothesis explains
Two established results predict opposite outcomes, and both cannot be right.
Does skin-barrier repair cause alternating underdelivery and damage, and can concentration-guided dosing prevent this at the same total dose?
Original wording · exactly as the pipeline generated it
Может ли восстановление барьера снижать доставку поддерживающего препарата настолько, что учащение нанесений запускает чередование недостаточной дозы и повреждения; устраняет ли коррекция по тканевой концентрации этот цикл при одинаковой суммарной дозе?
What this question is asking
The question concerns a skin treatment applied repeatedly to maintain an effect while the skin’s protective barrier changes. It asks whether barrier repair reduces the amount of medicine reaching skin tissue, prompting more frequent applications that cause damage and create a repeating cycle of inadequate delivery and injury. It then asks whether adjusting applications according to the amount of medicine measured in tissue stops that cycle, compared with a schedule using the same total applied amount without that adjustment. The surrounding rationale assumes that increasing delivery can harm the barrier, but whether repair, reduced delivery and repeated damage form this particular cycle remains to be established.
- Skin barrier
- The skin’s protective structure that limits entry of outside substances and loss of water. Barrier function can vary in degree; it is not simply present or absent.
- Barrier repair or restoration
- Recovery of the skin’s protective function after it has changed or been disrupted. Recovery in one measurement does not by itself establish how much medicine enters the skin.
- Skin permeability
- How readily a particular substance passes through the skin. The question asks whether changes in this property alter medicine delivery during repeated treatment.
- Maintenance treatment
- Repeated treatment intended to preserve an effect over time. No particular maintenance medicine is identified in the supplied question.
- Drug delivery and underdelivery
- Drug delivery is the passage of medicine to the tissue where it is intended to act. Underdelivery means that too little reaches that location to maintain the intended effect; the input supplies no threshold defining too little.
- Tissue concentration
- The amount of medicine present per amount or volume of tissue at a specified place and time. It differs from the amount applied to the skin surface.
- Concentration-guided dosing
- Adjusting the application schedule or individual application amounts using measured tissue concentration. The question does not specify the adjustment rule.
- Total applied dose
- The combined amount of medicine placed on the skin over the comparison period. Equal applied totals do not, by definition alone, establish equal amounts reaching tissue.
- Application frequency
- How often a treatment is placed on the skin. Increasing frequency does not specify whether the total applied dose increases unless the amount per application is also known.
- Penetration enhancer
- A substance used to increase medicine passage through the skin barrier. This names a class of substances, not one ingredient with a uniform effect.
- Ultrasound-assisted absorption
- Use of sound waves above the human hearing range to help medicine pass through the skin. S5 discusses disturbance of fats in the outer skin layer as a possible mechanism.
- Fats in the outer skin layer
- Barrier-forming fatty materials in the skin’s outermost layer. S5 proposes that disturbing these materials may allow greater medicine passage.
- Water loss through the skin
- A measurement of water escaping through the skin, used here as an indicator of barrier function. S10 reports its return to baseline, meaning its starting comparison level.
- Glyceryl monooleate and petrolatum
- Glyceryl monooleate is the ingredient tested as a penetration enhancer in S8; petrolatum is the petroleum-based material whose penetration was measured. That material-specific result does not establish how an unspecified maintenance medicine behaves.
- Skin damage
- Harm to skin structure or function. The question does not define its measurement, severity or duration, and a change in a barrier measurement does not automatically establish harmful injury.
- Youthful skin function
- The proposed target of maintaining skin performance at a level associated with younger people. The input does not identify the functions, reference population or measurements that define this target.
Increasing drug delivery can damage the skin barrier, creating a conflict between barrier restoration and sufficient delivery as skin permeability changes.
The skin barrier is the protective structure that limits substances entering through the skin, and permeability describes how readily substances pass through it. The rationale assumes that increasing passage can harm this protection, whereas restoring protection can reduce medicine delivery. If established, that trade-off would explain why maintaining both adequate treatment and an intact barrier might require changing the application schedule.
S1 supports the narrower point that the skin barrier limits entry. S5 describes disruption of fats in the outer skin layer as a possible explanation for ultrasound-assisted absorption, while explicitly stating that the exact mechanism is unknown. S10 reports that water loss through the skin returned to its starting level after a delivery enhancer was removed. These findings support a possible interaction between delivery methods and barrier function, but they do not establish harmful injury, reduced maintenance-drug delivery during repair, or the proposed repeating cycle.S1S5S10
The same question asked without the part nothing read establishes:
- During repeated skin treatment, does barrier recovery reduce medicine delivery, and does increasing application frequency then produce alternating inadequate delivery and damage?
- At the same total applied dose, does adjusting applications according to measured tissue concentration reduce inadequate delivery and skin damage compared with a schedule without that adjustment?
- The cycle occurs, and concentration-guided adjustment prevents it Under the proposed mechanism, barrier repair would reduce delivery and more frequent applications would contribute to renewed damage. Preventing both outcomes through concentration-guided adjustment at the same total dose would indicate that the application schedule, rather than an increase in total medicine applied, can resolve this conflict in the conditions examined.
- The cycle occurs, but concentration-guided adjustment does not prevent it Barrier repair and repeated application would still produce alternating inadequate delivery and damage. Measuring the amount in tissue and adjusting applications would therefore be insufficient to maintain both delivery and barrier protection under the conditions examined.
- The proposed cycle does not occur Barrier repair might leave delivery adequate, or more frequent applications might not produce the predicted alternation with damage. In that case, any difference between application schedules would require an explanation other than prevention of this particular cycle.
The proposed chain starts with a distinction between how much medicine is applied and how much reaches the tissue where it is intended to act. If barrier repair reduces delivery, an unchanged application schedule could cease to maintain the intended effect. If more frequent applications then damage the barrier and change delivery again, responding only to an apparent loss of effect could perpetuate unstable treatment. Conversely, assuming that this cycle exists without evidence could misattribute inadequate delivery or damage to barrier repair. The broader target is sustained youthful skin function with limited treatment burden and accumulated harm over ten years; none of the supplied findings establishes that outcome.
Усиление доставки RL-2 может повреждать барьер; коррекция по его состоянию и пространственная оценка экспозиции остаются на RL-1.
Функции остаются в молодой норме между процедурами; нагрузка и накопленный вред удерживаются ниже согласованных пределов на протяжении 10 лет.
Неизвестно, какие правила коррекции разрешают конфликт между восстановлением барьера и достаточной доставкой при меняющейся проницаемости кожи.
The mechanism it proposes
The engine's own statement of the hypothesis, in full.
Гипотеза о циклической конкуренции кожных микроорганизмов. Повторные нанесения препарата или его носителя меняют относительную приспособленность трех микробных стратегий: производителя антимикробного вещества P, устойчивого к нему штамма R и чувствительного быстрорастущего штамма S. Производитель вытесняет чувствительный штамм, устойчивый выигрывает у производителя за счет отсутствия затрат на производство, а чувствительный выигрывает у устойчивого благодаря отсутствию затрат на устойчивость. Если одна из стратегий одновременно выделяет повреждающую кожу протеазу, смена доминирования создает реальные волны повреждения и последующего восстановления с изменением доставки препарата. Состояние хранится в частотах стратегий и их конкурентных преимуществах. Для стабилизации SPV_9 необходимо разорвать цикл конкуренции; поддержание тканевой концентрации препарата само по себе его не устраняет.
Where the idea comes from
The hypothesis borrows a result from another field. This is what it borrows, and from where.
Эволюционная теория игр, репликаторная модель нетранзитивной конкуренции «камень, ножницы, бумага»: dx_i/dt = x_i[(Ax)_i - x^T A x]. Здесь t означает время в сутках; i принимает значения P, R, S; x_i означает долю жизнеспособных микроорганизмов стратегии i, сумма долей равна 1; A означает матрицу измеренных конкурентных выигрышей в сутки при заданных концентрациях препарата и носителя; A_ij означает вклад контакта с конкурентом j в относительную скорость роста стратегии i; (Ax)_i означает ее текущий выигрыш; x^T A x означает средний выигрыш сообщества. Проверяемый цикл преимуществ: P выигрывает у S, R у P, S у R. Повреждающую нагрузку связывают с конкуренцией через Q(t) = N(t)Σq_i x_i(t), где N означает общее число жизнеспособных микроорганизмов на см², q_i означает измеренную секрецию активной протеазы одной клеткой за сутки, Q означает суммарную секрецию на см² за сутки. Матрицу A оценивают независимо; не всякая такая матрица дает устойчивые колебания. Экспериментальный прецедент циклической бактериальной конкуренции получен вне кожи. [Kerr и соавторы, 2002](https://www.nature.com/articles/nature00823).
Testing and possible results
The prediction that would tell it apart
A hypothesis that predicts what its rivals predict is not worth running an experiment over. This is the observation on which this one differs.
В реконструированной коже при одинаковой тканевой экспозиции препарата изменение исходных пропорций P, R и S предсказуемо сдвигает время первого пика протеазы и повреждения. Удаление одного участника разрывает последовательность повторных пиков, а восстановление трехкомпонентного сообщества возвращает ее. Замена повреждающего штамма вариантом с выключенной протеазой сохраняет микробную конкуренцию, но устраняет повреждение кожи. Отсутствие нетранзитивных преимуществ в парных конкуренциях либо сохранение цикла повреждения в стерильной модели при прочих равных опровергнет эту гипотезу как достаточное объяснение.
Would tell it apart from at least one rival. The prediction specifies observable loss and restoration of repeated peaks, elimination of skin damage, and explicit rejection conditions. No rival prediction is supplied. Only a bench experiment would settle it.
What testing it would take
The engine's own read on whether this is testable with methods that already exist.
Сначала необходимо найти среди кожных изолятов три стратегии с нужными парными преимуществами. Их существование в конкретной коже и при выбранном препарате не предполагается установленным. Затем доступны совместное культивирование, абсолютный подсчет микроорганизмов и проверка протеазных вариантов на реконструированном эпидермисе. Перенос потенциально повреждающего сообщества человеку для начальной проверки не требуется.
Other explanations
Every other hypothesis the engine wrote for the same gap, and the observation that would separate the two.
В реконструированной коже при одинаковой тканевой экспозиции препарата изменение исходных пропорций P, R и S предсказуемо сдвигает время первого пика протеазы и повреждения. Удаление одного участника разрывает последовательность повторных пиков, а восстановление трехкомпонентного сообщества возвращает ее. Замена повреждающего штамма вариантом с выключенной протеазой сохраняет микробную конкуренцию, но устраняет повреждение кожи. Отсутствие нетранзитивных преимуществ в парных конкуренциях либо сохранение цикла повреждения в стерильной модели при прочих равных опровергнет эту гипотезу как достаточное объяснение.
- Rival 01 of 02What would separate them
Synchronized skin cell renewal may sustain cycles of barrier loss through coordinated shedding predicts: В стерильной органотипической модели после единственного синхронизирующего воздействия возникают как минимум три последовательные волны потери барьерной функции с незатухающей амплитудой при постоянной свободной концентрации препарата и отсутствии поверхностных продуктов окисления. Пики отшелушивания предшествуют пикам потери воды, а период соответствует измеренному времени прохождения клеточной когорты через эпидермис. Распределение первоначального воздействия во времени уменьшает амплитуду при той же суммарной дозе и сопоставимом среднем числе делений. Затухание волн после первой когорты опровергнет сильную версию гипотезы о самоподдерживающемся цикле.
- Rival 02 of 02What would separate them
Oxidation of a lipid carrier on skin may cause recurring damage as toxic products accumulate predicts: В стерильной модели без выраженной синхронизации клеточных когорт замена окисляемого носителя на устойчивый уменьшает повторные пики повреждения при сопоставимых свободной тканевой концентрации препарата, гидратации, окклюзии и световой нагрузке. Химически охарактеризованные продукты окисления, добавленные обратно в экспериментальной модели, возвращают повреждение. Пики гидропероксидов или альдегидов предшествуют повреждению. Если их образование подавлено и подтверждено аналитически, но цикл сохраняется без изменения амплитуды, гипотеза отвергается.
What stands behind it
Which of the figures above have a study behind them, which are the engine's own, and what it would take to refute the hypothesis. This audit never judges the idea.
This hypothesis states no figure and cites no study, so there is nothing here to trace.
What it would take to refute it. Nothing already retrieved carries the prediction’s terms and it names no measurement this layer can route to a public dataset, so the bench is the residual — not a finding against it.
6 papers retrieved around this hypothesis
- Housing displacement experiences following major flooding in regional Australia: A qualitative study of online news articles.PMID 42715233 · full_text · 89,757 characters stored
- Ten-year analysis of publications by Quebec hospital pharmacistseuropepmc:PMC:PMC13446782 · full_text · 3,860 characters stored
- Special Issue Editorial: "Antibacterial Agents from Natural Source, 2nd Edition".PMID 42738736 · full_text · 10,220 characters stored
- SARD: A Large-Scale Synthetic Arabic OCR Dataset for Book-Style Text Recognition.PMID 42760300 · full_text · 36,079 characters stored
- Characterizing Food Industry Affiliations Among Critics of the Nova Food Classification System: A Systematic Review.PMID 42753229 · full_text · 5,813 characters stored
- Something looks fishy! A philosophical exploration of AI for marine conservation.PMID 42687934 · full_text · 91,449 characters stored
0 citation handles extracted; 1 Europe PMC search run; 0 records examined; 0 sources stored for enrichment, 0 with full text. A citation that did not resolve is a bibliographic failure, not proof that no such paper exists, and no hypothesis is blocked by this audit.