>the physical non-reactive presence of particles can clog and get in the way of natural processes mechanically

Source?

TBH I can't remember what I was looking up when I first read about that (I feel like it was metals, glass, or cellulose again), but https://www.pnas.org/doi/10.1073/pnas.2104610118 seems pertinent:

> In general, mechanical interactions of microparticles and nanoparticles on biological membranes are vaguely studied, despite their importance for biological systems (29, 41). Hereby, we will demonstrate that these microplastics induce a mechanical stress of model cell membrane without the need of indirect assumptions about biological pathways (26, 27).

> physical non-reactive presence of particles can clog and get in the way of natural processes mechanically

That would mean fiber in food is harmful since it is not digested. Cellulose is just a common type of natural fiber. Meanwhile:

USDA recommends that people consume the following amounts of fiber per day:

-- Women ages 31–50: 25 grams

-- Men ages 31–50: 38 grams

No, it can't. Cellulose is the main type of insoluble dietary fiber, and is in leafy vegetables, beans, peas, and many other foods. It's widely accepted as being good for digestion. Too much fiber can cause constipation and gas, but most people probably don't get enough fiber, so that's rarely a problem.